Journal of Amino Acids http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition Tue, 14 Oct 2014 11:08:53 +0000 http://www.hindawi.com/journals/jaa/2014/269797/ Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs. Bimal Mohanty, Arabinda Mahanty, Satabdi Ganguly, T. V. Sankar, Kajal Chakraborty, Anandan Rangasamy, Baidyanath Paul, Debajit Sarma, Suseela Mathew, Kurukkan Kunnath Asha, Bijay Behera, Md. Aftabuddin, Dipesh Debnath, P. Vijayagopal, N. Sridhar, M. S. Akhtar, Neetu Sahi, Tandrima Mitra, Sudeshna Banerjee, Prasenjit Paria, Debajeet Das, Pushpita Das, K. K. Vijayan, P. T. Laxmanan, and A. P. Sharma Copyright © 2014 Bimal Mohanty et al. All rights reserved. Low-Vacuum Deposition of Glutamic Acid and Pyroglutamic Acid: A Facile Methodology for Depositing Organic Materials beyond Amino Acids Mon, 01 Sep 2014 06:21:04 +0000 http://www.hindawi.com/journals/jaa/2014/434056/ Thin layers of pyroglutamic acid (Pygl) have been deposited by thermal evaporation of the molten L-glutamic acid (L-Glu) through intramolecular lactamization. This deposition was carried out with the versatile handmade low-vacuum coater, which was simply composed of a soldering iron placed in a vacuum degassing resin chamber evacuated by an oil-free diaphragm pump. Molecular structural analyses have revealed that thin solid film evaporated from the molten L-Glu is mainly composed of L-Pygl due to intramolecular lactamization. The major component of the L-Pygl was in -phase and the minor component was in -phase, which would have been generated from partial racemization to DL-Pygl. Electron microscopy revealed that the L-Glu-evaporated film generally consisted of the 20 nm particulates of Pygl, which contained a periodic pattern spacing of 0.2 nm intervals indicating the formation of the single-molecular interval of the crystallized molecular networks. The DL-Pygl-evaporated film was composed of the original DL-Pygl preserving its crystal structures. This methodology is promising for depositing a wide range of the evaporable organic materials beyond amino acids. The quartz crystal resonator coated with the L-Glu-evaporated film exhibited the pressure-sensing capability based on the adsorption-desorption of the surrounding gas at the film surface. Iwao Sugimoto, Shunsaku Maeda, Yoriko Suda, Kenji Makihara, and Kazuhiko Takahashi Copyright © 2014 Iwao Sugimoto et al. All rights reserved. Interaction of Ingested Leucine with Glycine on Insulin and Glucose Concentrations Thu, 10 Jul 2014 12:14:14 +0000 http://www.hindawi.com/journals/jaa/2014/521941/ The majority of individual amino acids increase insulin and attenuate the plasma glucose response when ingested with glucose. Objective. To determine whether ingestion of two amino acids simultaneously, with glucose, would result in an additive effect. Leucine (Leu) and glycine (Gly) were chosen because they were two of the most potent glucose-lowering amino acids when given individually. Materials and Methods. Nine subjects received test items on four separate days. The first was a water control, then 25 g glucose, or Leu + Gly (1 mmol/kg fat-free mass each) ±25 g glucose, in random order. Glucose, insulin, and glucagon were measured frequently for 2.5 hours. Net areas were calculated. Results. The glucose area response decreased by 66%. The insulin area response increased by 24% after ingestion of Leu + Gly + glucose compared to ingestion of glucose alone. The decrease in glucose response was not additive; the increase in insulin response was far less than additive when compared to previously published individual amino acid results. The glucagon concentration remained unchanged. Conclusion. There is an interaction between Leu and Gly that results in a markedly attenuated glucose response. This occurred with a very modest increase in insulin response. Changes in glucagon response could not explain the results. The mechanism is unknown. Jennifer F. Iverson, Mary C. Gannon, and Frank Q. Nuttall Copyright © 2014 Jennifer F. Iverson et al. All rights reserved. In Silico Analysis of -Galactosidases Primary and Secondary Structure in relation to Temperature Adaptation Mon, 24 Mar 2014 14:08:12 +0000 http://www.hindawi.com/journals/jaa/2014/475839/ β-D-Galactosidases (EC 3.2.1.23) hydrolyze the terminal nonreducing β-D-galactose residues in β-D-galactosides and are ubiquitously present in all life forms including extremophiles. Eighteen microbial β-galactosidase protein sequences, six each from psychrophilic, mesophilic, and thermophilic microbes, were analyzed. Primary structure reveals alanine, glycine, serine, and arginine to be higher in psychrophilic β-galactosidases whereas valine, glutamine, glutamic acid, phenylalanine, threonine, and tyrosine are found to be statistically preferred by thermophilic β-galactosidases. Cold active β-galactosidase has a strong preference towards tiny and small amino acids, whereas high temperature inhabitants had higher content of basic and aromatic amino acids. Thermophilic β-galactosidases have higher percentage of α-helix region responsible for temperature tolerance while cold loving β-galactosidases had higher percentage of sheet and coil region. Secondary structure analysis revealed that charged and aromatic amino acids were significant for sheet region of thermophiles. Alanine was found to be significant and high in the helix region of psychrophiles and valine counters in thermophilic β-galactosidase. Coil region of cold active β-galactosidase has higher content of tiny amino acids which explains their high catalytic efficiency over their counterparts from thermal habitat. The present study has revealed the preference or prevalence of certain amino acids in primary and secondary structure of psychrophilic, mesophilic, and thermophilic β-galactosidase. Vijay Kumar, Nikhil Sharma, and Tek Chand Bhalla Copyright © 2014 Vijay Kumar et al. All rights reserved. Lauryl-poly-L-lysine: A New Antimicrobial Agent? Sun, 23 Feb 2014 13:32:54 +0000 http://www.hindawi.com/journals/jaa/2014/672367/ The development of multiple antibiotic resistance is a global problem. It is necessary to find new tools whose mechanisms of action differ from those of currently used antibiotics. It is known that fatty acids and cationic polypeptides are able to fight bacteria. Here, we describe the synthesis of fatty acids linked to a polypeptide with antibacterial activity. The linkage of fatty acids to a polypeptide is reported to increase the antibacterial effect of the linked fatty acid in comparison with free fatty acids (FA) or free poly-L-lysine (PLL) or a mixture of both (FA free + PLL free). A number of C6–C18 fatty acids were linked to PLL to obtain new synthetic products. These compounds were assessed in vitro to evaluate their antibacterial activity. Some fatty acid-PLLs showed a good ability to fight bacteria. Their bactericidal activity was evaluated, and, lauryl linked to PLL was found to be the most active product against both Gram-positive and Gram-negative bacteria. This new active component showed a good degree of specificity and reproducibility and its minimum inhibitory concentration (MIC) was comparatively good. The antibacterial activity of the lauryl-PLL compound suggests that it is a new and promising antimicrobial agent. Laetitia Vidal, Véronique Thuault, Arturo Mangas, Rafael Coveñas, Anne Thienpont, and Michel Geffard Copyright © 2014 Laetitia Vidal et al. All rights reserved. L-Phenylalanine Transport in Saccharomyces cerevisiae: Participation of GAP1, BAP2, and AGP1 Thu, 20 Feb 2014 12:57:31 +0000 http://www.hindawi.com/journals/jaa/2014/283962/ We focused on the participation of GAP1, BAP2, and AGP1 in L-phenylalanine transport in yeast. In order to study the physiological functions of GAP1, BAP2, and AGP1 in L-phenylalanine transport, we examined the kinetics, substrate specificity, and regulation of these systems, employing isogenic haploid strains with the respective genes disrupted individually and in combination. During the characterization of phenylalanine transport, we noted important regulatory phenomena associated with these systems. Our results show that Agp1p is the major transporter of the phenylalanine in a gap1 strain growing in synthetic media with leucine present as an inducer. In a wild type strain grown in the presence of leucine, when ammonium ion was the nitrogen source, Bap2p is the principal phenylalanine carrier. Daniel A. Sáenz, Mónica S. Chianelli, and Carlos A. Stella Copyright © 2014 Daniel A. Sáenz et al. All rights reserved. Immune Activation and Inflammation in Patients with Cardiovascular Disease Are Associated with Higher Phenylalanine to Tyrosine Ratios: The Ludwigshafen Risk and Cardiovascular Health Study Mon, 10 Feb 2014 07:50:31 +0000 http://www.hindawi.com/journals/jaa/2014/783730/ Higher serum neopterin is associated with increased mortality in patients with coronary artery disease (CAD). Preferentially Th1-type cytokine interferon-γ stimulates neopterin production by GTP cychlohydrolase I (GCH-I) in parallel in monocyte-derived macrophages and dendritic cells. In other cells, activation of GCH-I leads to the formation of 5,6,7,8-tetrahydrobiopterin (BH4), the necessary cofactor of amino acid hydroxylases like phenylalanine 4-hydroxylase (PAH). Serum concentrations of phenylalanine, tyrosine, neopterin, and high sensitivity C-reactive protein (hsCRP) were measured in 1196 patients derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study, a cohort study among patients referred for coronary angiography. The phenylalanine to tyrosine ratio (Phe/Tyr) served as an estimate of phenylalanine hydroxylase (PAH) enzyme activity. Serum concentrations of phenylalanine and tyrosine and of Phe/Tyr did not differ between individuals with or without CAD (Welch's -test: = n.s.). Higher neopterin and hsCRP concentrations were observed in CAD patients compared to controls () and they correlated with Phe/Tyr (Spearman's rank correlation for neopterin: = 0.216 and hsCRP: = 0.122; both of ) concentrations. In conclusion, immune activation is associated with higher Phe/Tyr in CAD patients. Data indicates subnormal PAH activity which might be involved in the precipitation of neuropsychiatric symptoms in patients. Christian Murr, Tanja B. Grammer, Andreas Meinitzer, Marcus E. Kleber, Winfried März, and Dietmar Fuchs Copyright © 2014 Christian Murr et al. All rights reserved. Development of a Novel Cysteine Sulfinic Acid Decarboxylase Knockout Mouse: Dietary Taurine Reduces Neonatal Mortality Mon, 03 Feb 2014 10:19:02 +0000 http://www.hindawi.com/journals/jaa/2014/346809/ We engineered a CSAD KO mouse to investigate the physiological roles of taurine. The disruption of the CSAD gene was verified by Southern, Northern, and Western blotting. HPLC indicated an 83% decrease of taurine concentration in the plasma of CSAD. Although CSAD generation (G)1 and G2 survived, offspring from G2 CSAD had low brain and liver taurine concentrations and most died within 24 hrs of birth. Taurine concentrations in G3 CSAD born from G2 CSAD treated with taurine in the drinking water were restored and survival rates of G3 CSAD increased from 15% to 92%. The mRNA expression of CDO, ADO, and TauT was not different in CSAD compared to WT and CSAD mRNA was not expressed in CSAD. Expression of Gpx 1 and 3 was increased significantly in CSAD and restored to normal levels with taurine supplementation. Lactoferrin and the prolactin receptor were significantly decreased in CSAD. The prolactin receptor was restored with taurine supplementation. These data indicated that CSAD KO is a good model for studying the effects of taurine deficiency and its treatment with taurine supplementation. Eunkyue Park, Seung Yong Park, Carl Dobkin, and Georgia Schuller-Levis Copyright © 2014 Eunkyue Park et al. All rights reserved. Acute Effects of an Energy Drink on Myocardial Function Assessed by Conventional Echo-Doppler Analysis and by Speckle Tracking Echocardiography on Young Healthy Subjects Sun, 10 Nov 2013 09:09:22 +0000 http://www.hindawi.com/journals/jaa/2013/646703/ Purpose. Previous studies have underlined the effects of the energy drinks containing caffeine end taurine on the cardiovascular system. The aim of this study was to determine acute changes on echocardiographic parameters assessed by conventional echo-Doppler analysis and by speckle tracking echocardiography after the consumption of an energy drink in a young healthy population. Methods. measurement of blood pressure, electrocardiographic, and echocardiographic examination were performed on 35 healthy subjects (mean age 25 ± 2 years, 16 men), at baseline and one hour after the consumption of a body surface area indexed amount of an energy drink (168 mL/m2) containing caffeine (0.03%) and taurine (0.4%). Results. The analysis of left ventricular function showed a significant increase of mean relative values of MAPSE (+11%; ), global longitudinal strain (+10%, ), and left ventricular twisting (+22%, ) in respect to baseline. Also, right ventricular function parameters appeared significantly increased after energy drink consumption, as TAPSE (+15%, ), global, and free wall right ventricular longitudinal strain (+8%, ; +5%, , resp.). Conclusion. In conclusion, the consumption of the ED in our population showed a significant increase of right and left ventricular myocardial function, suggesting a possible positive inotropic effect related to the substances contained therein. Daniele Menci, Francesca Maria Righini, Matteo Cameli, Matteo Lisi, Susanna Benincasa, Marta Focardi, and Sergio Mondillo Copyright © 2013 Daniele Menci et al. All rights reserved. In Silico Insights of L-Glutamate: Structural Features in Vacuum and in Complex with Its Receptor Wed, 06 Nov 2013 14:32:39 +0000 http://www.hindawi.com/journals/jaa/2013/872058/ Structural properties of the glutamate in vacuum and in complex with its receptor were analyzed. The analysis was focused on global properties, attempting to characterize features such as overall flexibility and common trends in the conformation set. The glutamate, as other ligands in complex with the receptor, adopts a spatial conformation that corresponds to one of the possible molecular equilibrium states in physiological conditions. The glutamate forms an extended structure for all cases, but the energy of the glutamate round out form is lower than the extended glutamate form. The results showed the glutamate as a flexible molecule, which can easily adapt to different interacting environments, and it can be considered as an approximation to address why glutamate interacts with a great number of molecules. Janneth Gonzalez and George E. Barreto Copyright © 2013 Janneth Gonzalez and George E. Barreto. All rights reserved. Long-Lasting Effects of Oxy- and Sulfoanalogues of L-Arginine on Enzyme Actions Thu, 24 Oct 2013 15:24:52 +0000 http://www.hindawi.com/journals/jaa/2013/407616/ Arginine residues are very important for the structure of proteins and their action. Arginine is essential for many natural processes because it has unique ionizable group under physiological conditions. Numerous mimetics of arginine were synthesized and their biological effects were evaluated, but the mechanisms of actions are still unknown. The aim of this study is to see if oxy- and sulfoanalogues of arginine can be recognized by human arginyl-tRNA synthetase (HArgS)—an enzyme responsible for coupling of L-arginine with its cognate tRNA in a two-step catalytic reaction. We make use of modeling and docking studies of adenylate kinase (ADK) to reveal the effects produced by the incorporation of the arginine mimetics on the structure of ADK and its action. Three analogues of arginine, L-canavanine (Cav), L-norcanavanine (NCav), and L-sulfoarginine (sArg), can be recognized as substrates of HArgS when incorporated in different peptide and protein sequences instead of L-arginine. Mutation in the enzyme active center by arginine mimetics leads to conformational changes, which produce a decrease the rate of the enzyme catalyzed reaction and even a loss of enzymatic action. All these observations could explain the long-lasting nature of the effects of the arginine analogues. Tatyana A. Dzimbova, Peter B. Milanov, and Tamara I. Pajpanova Copyright © 2013 Tatyana A. Dzimbova et al. All rights reserved. (R)-α-Aminoadipic Acid: A Versatile Precursor for the Synthesis of D-Amino Acids Thu, 10 Oct 2013 15:42:48 +0000 http://www.hindawi.com/journals/jaa/2013/252813/ The ready accessibility of (R)-α-aminoadipic acid by enzymatic cleavage of cephalosporin C (CephC) in the production of 7-aminocephalosporanic acid (7-ACA) on a large scale makes it a favorable chiral pool building block for the synthesis of unusual amino acids. A route for the synthesis of C-5-alkenyl and C-6-alkylidene derivatives of (R)-pipecolic acid is described which utilizes (R)-α-aminoadipic acid as the enantiomerically pure starting material. Moreover, the synthesis of azido and triazolyl derivatives of (R)-α-aminoadipic acid is reported. Amina Sadiq and Norbert Sewald Copyright © 2013 Amina Sadiq and Norbert Sewald. All rights reserved. Cdc48: A Swiss Army Knife of Cell Biology Sun, 15 Sep 2013 14:32:14 +0000 http://www.hindawi.com/journals/jaa/2013/183421/ Cdc48 (also called VCP and p97) is an abundant protein that plays essential regulatory functions in a broad array of cellular processes. Working with various cofactors, Cdc48 utilizes its ATPase activity to promote the assembly and disassembly of protein complexes. Here, we review key biological functions and regulation of Cdc48 in ubiquitin-related events. Given the broad employment of Cdc48 in cell biology and its intimate ties to human diseases (e.g., amyotrophic lateral sclerosis), studies of Cdc48 will bring significant insights into the mechanism and function of ubiquitin in health and diseases. Guem Hee Baek, Haili Cheng, Vitnary Choe, Xin Bao, Jia Shao, Shiwen Luo, and Hai Rao Copyright © 2013 Guem Hee Baek et al. All rights reserved. Total 4EBP1 Is Elevated in Liver of Rats in Response to Low Sulfur Amino Acid Intake Sun, 08 Sep 2013 14:57:27 +0000 http://www.hindawi.com/journals/jaa/2013/864757/ Translation initiation is known to be regulated by the binding of eukaryotic initiation factor 4E (eIF4E) by binding proteins (4EBPs), and there is evidence that amino acid deprivation and other cellular stresses upregulate 4EBP1 expression. To pursue the question of whether diets limited in an essential amino acid lead to induction of 4EBP1 expression in vivo, diets that varied in methionine and cystine content were fed to rats for 7 days, and 4EBP1 mRNA and protein levels and 4EBP1 phosphorylation state were determined. Total 4EBP1 mRNA and protein abundance increased in liver of rats with severely deficient intakes of sulfur amino acids (0.23% or 0.11% methionine without cystine) but not in animals with a less restricted intake of sulfur amino acids (0.11% methionine plus 0.35% cystine) but a similarly restricted intake of total diet (53 to 62% of control). The amount of 4EBP1 binding activity (α + β forms) was elevated in liver of rats fed sulfur amino acid-deficient diets, whereas the hyperphosphorylation of 4EBP1 was not affected by dietary treatment. Results suggest that changes in total 4EBP1 expression should be considered when examining mechanisms that attenuate protein synthesis during amino acid deficiency states. Angelos K. Sikalidis, Kevin M. Mazor, Minji Kang, Hongyun Liu, and Martha H. Stipanuk Copyright © 2013 Angelos K. Sikalidis et al. All rights reserved. Ingestion of Leucine + Phenylalanine with Glucose Produces an Additive Effect on Serum Insulin but Less than Additive Effect on Plasma Glucose Mon, 29 Jul 2013 09:27:23 +0000 http://www.hindawi.com/journals/jaa/2013/964637/ Most individual amino acids stimulate insulin secretion and attenuate the plasma glucose response when ingested with glucose. We determined whether ingestion of two amino acids simultaneously with glucose would result in an additive effect on the glucose area response compared with ingestion of amino acids individually. Leucine and phenylalanine were chosen because they were two of the most potent glucose-lowering amino acids when given individually. Eight healthy subjects were studied on four separate days. Test meals were given at 0800. The first meal was a water control. Subjects then received 25 g glucose or leucine + phenylalanine (1 mmol/kg fat free body mass each) ±25 g glucose in random order. Glucose, insulin and glucagon were measured frequently for 2.5 hours thereafter. Net areas under the curves were calculated using the mean fasting value as baseline. The insulin response to leucine + phenylalanine was additive. In contrast, the decrease in glucose response to leucine + phenylalanine + glucose was less than additive compared to the individual amino acids ingested with glucose. Interestingly, the insulin response to the combination was largely due to the leucine component, whereas the glucose response was largely due to the phenylalanine component. Glucose was unchanged when leucine or phenylalanine, alone or in combination, was ingested without glucose. This trial is registered with ClinicalTrials.gov NCT01471509. Jennifer F. Iverson, Mary C. Gannon, and Frank Q. Nuttall Copyright © 2013 Jennifer F. Iverson et al. All rights reserved. An Amino Acids Mixture Improves the Hepatotoxicity Induced by Acetaminophen in Mice Wed, 26 Jun 2013 11:38:16 +0000 http://www.hindawi.com/journals/jaa/2013/615754/ Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, but at high dose it leads to undesirable side effects, such as hepatotoxicity and nephrotoxicity. The aim of this study was to evaluate the protective role of DDM-GSH, a mixture of L-cysteine, L-methionine, and L-serine in a weight ratio of 2 : 1 : 1, in comparison to N-acetylcysteine (NAC), against acetaminophen- (APAP-) induced hepatotoxicity in mice. Toxicity was induced in mice by the intraperitoneal (ip) administration of low dose (2 mmol/kg) or high dose (8 mmol/kg) of APAP. DDM-GSH (0.4 to 1.6 mmol/kg) was given ip to mice 1 h before the APAP administration. The same was done with NAC (0.9 to 3.6 mmol/kg), the standard antidote of APAP toxicity. Mice were sacrificed 8 h after the APAP injection to determine liver weight, serum alanine aminotransferase (ALT), and total glutathione (GSH) depletion and malondialdehyde (MDA) accumulation in liver tissues. DDM-GSH improved mouse survival rates better than NAC against a high dose of APAP. Moreover, DDM-GSH significantly reduced in a dose-dependent manner not only APAP-induced increases of ALT but also APAP-induced hepatic GSH depletion and MDA accumulation. Our results suggest that DDM-GSH may be more potent than NAC in protecting the liver from APAP-induced liver injury. Francesco Di Pierro and Giuseppe Rossoni Copyright © 2013 Francesco Di Pierro and Giuseppe Rossoni. All rights reserved. An Evaluation of Interindividual Responses to the Orally Administered Neurotransmitter β-Alanine Sun, 23 Jun 2013 08:51:17 +0000 http://www.hindawi.com/journals/jaa/2013/429847/ Previously, we have identified β-alanine as a potential endogenous anticonvulsant molecule. β-Alanine occurs within the human central nervous system and has been identified as both an inhibitory neuromodulator and neurotransmitter that is bioavailable to brain after oral administration. During preliminary compounding trials to ascertain dosing strategies for β-alanine, we noted pronounced differences in the side effect profile experienced by individuals of Asian and Caucasian descent. To investigate whether ethnicity affects β-alanine-induced side effects, we administered 3 g of β-alanine in 200 mL of fruit drink to ten people of each ethnic background and observed them for 30 minutes. Data collected included basic physical statistics (height, age, and weight) and descriptions of all side effects, as reported by participants. We found that participants of Asian descent experienced paraesthesia, but significantly different in time of onset, intensity, and anatomical localization, as compared to the effects experienced by Caucasian participants. Since β-alanine is an endogenous neurotransmitter substance within human brain, these side effect differences were unexpected. Sarah MacPhee, Ian N. Weaver, and Donald F. Weaver Copyright © 2013 Sarah MacPhee et al. All rights reserved. Bioactive Peptides in Cancer: Therapeutic Use and Delivery Strategies Wed, 15 May 2013 15:05:12 +0000 http://www.hindawi.com/journals/jaa/2013/568953/ Paola Stiuso, Michele Caraglia, Giuseppe De Rosa, and Antonio Giordano Copyright © 2013 Paola Stiuso et al. All rights reserved. DTNQ-Pro, a Mimetic Dipeptide, Sensitizes Human Colon Cancer Cells to 5-Fluorouracil Treatment Sun, 21 Apr 2013 15:43:03 +0000 http://www.hindawi.com/journals/jaa/2013/509056/ The resistance of growing human colon cancer cells to chemotherapy agents has been correlated to endogenous overexpression of stress proteins including the family of heat shock proteins (HSPs). Previously, we have demonstrated that a quinone-based mimetic dipeptide, named DTNQ-Pro, induced differentiation of growing Caco-2 cells through inhibition of HSP70 and HSP90. In addition, our product induced a HSP27 and vimentin intracellular redistribution. In the present study, we have evaluated whether a decrease of stress proteins induced by DTNQ-Pro in Caco-2 cells could sensitize these cells to treatment with 5-fluorouracil (5-FU) cytotoxicity. The pretreatment of Caco-2 with 500 nM of DTNQ-Pro increases lipid peroxidation and decreases expression of p38 mitogen-activated protein kinase (MAPK) and FOXO3a. At the same experimental conditions, an increase of the 5-FU-induced growth inhibition of Caco-2 cells was recorded. These effects could be due to enhanced DTNQ-Pro-induced membrane lipid peroxidation that, in turn, causes the sensitization of cancer cells to the cytotoxicity mediated by 5-FU. Isabel Gomez-Monterrey, Pietro Campiglia, Ilaria Scognamiglio, Daniela Vanacore, Alessandra Dicitore, Angela Lombardi, Michele Caraglia, Ettore Novellino, and Paola Stiuso Copyright © 2013 Isabel Gomez-Monterrey et al. All rights reserved. Ethanol- and/or Taurine-Induced Oxidative Stress in Chick Embryos Thu, 21 Mar 2013 11:37:27 +0000 http://www.hindawi.com/journals/jaa/2013/240537/ Because taurine alleviates ethanol- (EtOH-) induced lipid peroxidation and liver damage in rats, we asked whether exogenous taurine could alleviate EtOH-induced oxidative stress in chick embryos. Exogenous EtOH (1.5 mmol/Kg egg or 3 mmol/Kg egg), taurine (4 mol/Kg egg), or EtOH and taurine (1.5 mmol EtOH and 4 mol taurine/Kg egg or 3 mmol EtOH and 4 mol taurine/Kg egg) were injected into fertile chicken eggs during the first three days of embryonic development (E0–2). At 11 days of development (midembryogenesis), serum taurine levels and brain caspase-3 activities, homocysteine (HoCys) levels, reduced glutathione (GSH) levels, membrane fatty acid composition, and lipid hydroperoxide (LPO) levels were measured. Early embryonic EtOH exposure caused increased brain apoptosis rates (caspase-3 activities); increased brain HoCys levels; increased oxidative-stress, as measured by decreased brain GSH levels; decreased brain long-chain polyunsaturated levels; and increased brain LPO levels. Although taurine is reported to be an antioxidant, exogenous taurine was embryopathic and caused increased apoptosis rates (caspase-3 activities); increased brain HoCys levels; increased oxidative-stress (decreased brain GSH levels); decreased brain long-chain polyunsaturated levels; and increased brain LPO levels. Combined EtOH and taurine treatments also caused increased apoptosis rates and oxidative stress. Emily J. Berning, Noah Bernhardson, Kelly Coleman, Dina A. Farhat, Courtney M. Gushrowski, Alison Lanctot, Benjamin H. Maddock, Kathryn G. Michels, Luke A. Mugge, Catherine M. Nass, Sarah M. Yearsley, and Robert R. Miller Jr. Copyright © 2013 Emily J. Berning et al. All rights reserved. Amino Acid Derivatives as New Zinc Binding Groups for the Design of Selective Matrix Metalloproteinase Inhibitors Sun, 10 Mar 2013 15:06:29 +0000 http://www.hindawi.com/journals/jaa/2013/178381/ A number of matrix metalloproteinases (MMPs) are important medicinal targets for conditions ranging from rheumatoid arthritis to cardiomyopathy, periodontal disease, liver cirrhosis, multiple sclerosis, and cancer invasion and metastasis, where they showed to have a dual role, inhibiting or promoting important processes involved in the pathology. MMPs contain a zinc (II) ion in the protein active site. Small-molecule inhibitors of these metalloproteins are designed to bind directly to the active site metal ions. In an effort to devise new approaches to selective inhibitors, in this paper, we describe the synthesis and preliminary biological evaluation of amino acid derivatives as new zinc binding groups (ZBGs). The incorporation of selected metal-binding functions in more complex biphenyl sulfonamide moieties allowed the identification of one compound able to interact selectively with different MMP enzymatic isoforms. Mariateresa Giustiniano, Paolo Tortorella, Mariangela Agamennone, Antonella Di Pizio, Armando Rossello, Elisa Nuti, Isabel Gomez-Monterrey, Ettore Novellino, Pietro Campiglia, Ermelinda Vernieri, Marina Sala, Alessia Bertamino, and Alfonso Carotenuto Copyright © 2013 Mariateresa Giustiniano et al. All rights reserved. Potential Anticarcinogenic Peptides from Bovine Milk Tue, 26 Feb 2013 16:31:38 +0000 http://www.hindawi.com/journals/jaa/2013/939804/ Bovine milk possesses a protein system constituted by two major families of proteins: caseins (insoluble) and whey proteins (soluble). Caseins (αS1, αS2, β, and κ) are the predominant phosphoproteins in the milk of ruminants, accounting for about 80% of total protein, while the whey proteins, representing approximately 20% of milk protein fraction, include β-lactoglobulin, α-lactalbumin, immunoglobulins, bovine serum albumin, bovine lactoferrin, and lactoperoxidase, together with other minor components. Different bioactivities have been associated with these proteins. In many cases, caseins and whey proteins act as precursors of bioactive peptides that are released, in the body, by enzymatic proteolysis during gastrointestinal digestion or during food processing. The biologically active peptides are of particular interest in food science and nutrition because they have been shown to play physiological roles, including opioid-like features, as well as immunomodulant, antihypertensive, antimicrobial, antiviral, and antioxidant activities. In recent years, research has focused its attention on the ability of these molecules to provide a prevention against the development of cancer. This paper presents an overview of antitumor activity of caseins and whey proteins and derived peptides. Giacomo Pepe, Gian Carlo Tenore, Raffaella Mastrocinque, Paola Stusio, and Pietro Campiglia Copyright © 2013 Giacomo Pepe et al. All rights reserved. Design, Synthesis, and Evaluation of New Tripeptides as COX-2 Inhibitors Tue, 26 Feb 2013 15:51:16 +0000 http://www.hindawi.com/journals/jaa/2013/606282/ Cyclooxygenase (COX) is a key enzyme in the biosynthetic pathway leading to the formation of prostaglandins, which are mediators of inflammation. It exists mainly in two isoforms COX-1 and COX-2. The conventional nonsteroidal anti-inflammatory drugs (NSAIDs) have gastrointestinal side effects because they inhibit both isoforms. Recent data demonstrate that the overexpression of these enzymes, and in particular of cyclooxygenases-2, promotes multiple events involved in tumorigenesis; in addition, numerous studies show that the inhibition of cyclooxygenases-2 can delay or prevent certain forms of cancer. Agents that inhibit COX-2 while sparing COX-1 represent a new attractive therapeutic development and offer a new perspective for a further use of COX-2 inhibitors. The present study extends the evaluation of the COX activity to all 203 possible natural tripeptide sequences following a rational approach consisting in molecular modeling, synthesis, and biological tests. Based on data obtained from virtual screening, only those peptides with better profile of affinity have been selected and classified into two groups called S and E. Our results suggest that these novel compounds may have potential as structural templates for the design and subsequent development of the new selective COX-2 inhibitors drugs. Ermelinda Vernieri, Isabel Gomez-Monterrey, Ciro Milite, Paolo Grieco, Simona Musella, Alessia Bertamino, Ilaria Scognamiglio, Stefano Alcaro, Anna Artese, Francesco Ortuso, Ettore Novellino, Marina Sala, and Pietro Campiglia Copyright © 2013 Ermelinda Vernieri et al. All rights reserved. Urotensin-II Ligands: An Overview from Peptide to Nonpeptide Structures Mon, 25 Feb 2013 17:23:41 +0000 http://www.hindawi.com/journals/jaa/2013/979016/ Urotensin-II was originally isolated from the goby urophysis in the 1960s as a vasoactive peptide with a prominent role in cardiovascular homeostasis. The identification of human isoform of urotensin-II and its specific UT receptor by Ames et al. in 1999 led to investigating the putative role of the interaction U-II/UT receptor in multiple pathophysiological effects in humans. Since urotensin-II is widely expressed in several peripheral tissues including cardiovascular system, the design and development of novel urotensin-II analogues can improve knowledge about structure-activity relationships (SAR). In particular, since the modulation of the U-II system offers a great potential for therapeutic strategies related to the treatment of several diseases, like cardiovascular diseases, the research of selective and potent ligands at UT receptor is more fascinating. In this paper, we review the developments of peptide and nonpeptide U-II structures so far developed in order to contribute also to a more rational and detectable design and synthesis of new molecules with high affinity at the UT receptor. Francesco Merlino, Salvatore Di Maro, Ali Munaim Yousif, Michele Caraglia, and Paolo Grieco Copyright © 2013 Francesco Merlino et al. All rights reserved. Peptide Mass Fingerprinting and N-Terminal Amino Acid Sequencing of Glycosylated Cysteine Protease of Euphorbia nivulia Buch.-Ham. Sun, 17 Feb 2013 10:39:06 +0000 http://www.hindawi.com/journals/jaa/2013/569527/ A new cysteine protease named Nivulian-II has been purified from the latex of Euphorbia nivulia Buch.-Ham. The apparent molecular mass of Nivulian-II is 43670.846 Da (MALDI TOF/MS). Peptide mass fingerprint analysis revealed peptide matches to Maturase K (Q52ZV1_9MAGN) of Banksia quercifolia. The N-terminal sequence (DFPPNTCCCICC) showed partial homology with those of other cysteine proteinases of biological origin. This is the first paper to characterize a Nivulian-II of E. nivulia latex with respect to amino acid sequencing. Shamkant B. Badgujar and Raghunath T. Mahajan Copyright © 2013 Shamkant B. Badgujar and Raghunath T. Mahajan. All rights reserved. Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression Mon, 04 Feb 2013 15:55:07 +0000 http://www.hindawi.com/journals/jaa/2013/461901/ Catabolite repression (CCR) regulates amino acid permeases in Saccharomyces cerevisiae via a TOR-kinase mediated mechanism. When glucose, the preferred fuel in S. cerevisiae, is substituted by galactose, amino acid uptake is increased. Here we have assessed the contribution and metabolic significance of this surfeit of amino acid in yeast undergoing catabolite derepression (CDR). L-[U-14C]leucine oxidation was increased 15 ± 1 fold in wild type (WT) strain grown in galactose compared to glucose. Under CDR, leucine oxidation was (i) proportional to uptake, as demonstrated by decreased uptake and oxidation of leucine in strains deleted of major leucine permeases and (ii) entirely dependent upon the TCA cycle, as cytochrome c1 (Cyt1) deleted strains could not grow in galactose. A regulator of amino acid carbon entry into the TCA cycle, branched chain ketoacid dehydrogenase, was also increased 29 ± 3 fold under CCR in WT strain. Protein expression of key TCA cycle enzymes, citrate synthase (Cs), and Cyt1 was increased during CDR. In summary, CDR upregulation of amino acid uptake is accompanied by increased utilization of amino acids for yeast growth. The mechanism for this is likely to be an increase in protein expression of key regulators of the TCA cycle. John S. Hothersall and Aamir Ahmed Copyright © 2013 John S. Hothersall and Aamir Ahmed. All rights reserved. Binding Stoichiometry of a Recombinant Selenophosphate Synthetase with One Synonymic Substitution E197D to a Fluorescent Nucleotide Analog of ATP, TNP-ATP Wed, 30 Jan 2013 11:05:34 +0000 http://www.hindawi.com/journals/jaa/2013/983565/ The transformation of the strain - with plasmid vector pET11a containing the cloned gene of bacterial selenophosphate synthetase (SPS), selD, from the E. coli BL21-Gold (DE3) strain gives an overproducing strain of SPS with one synonymic substitution, E197D. The transformation efficiency was estimated as 8 × 108 CFU/μg plasmid DNA. 28 mg of highly purified preparation of recombinant SPS capable of binding TNP-ATP was eluted from DEAE-Sephadex column in amount of 15 % from the total soluble protein in crude extract. The fluorescent derivative of ATP, 2′(3′)-O-(2,4,6-trinitrophenyl)adenosine-5′-triphosphate (TNP-ATP), was used as a synthetic analog of the substrate for the monitoring and quantitative analysis of the functional activity of SPS. The non-linear regression analysis of the saturation curve of TNP-ATP binding to D197 SPS with GraphPad Prism software fits to a model with 2 distinct binding sites with different in order. The SPS existence in a form of tetramer in given reaction conditions, in accordance with the concentration stoichiometry of 4 moles of TNP-ATP to 1 mole of recombinant protein, is being discussed. The tetramer structure was predicted with molecular modelling software YASARA and modelled in vacuum using steepest descent minimization energy method. We hypothesize here the recombinant SPS exists as a dimer in solution with two active sites capable of ATP binding in each subunit. Y. V. Preobrazhenskaya, A. I. Stenko, M. V. Shvarts, and V. Y. Lugovtsev Copyright © 2013 Y. V. Preobrazhenskaya et al. All rights reserved. The Antitumor Peptide CIGB-552 Increases COMMD1 and Inhibits Growth of Human Lung Cancer Cells Wed, 16 Jan 2013 10:43:00 +0000 http://www.hindawi.com/journals/jaa/2013/251398/ We have demonstrated that the peptide L-2 designed from an alanine scanning of the Limulus-derived LALF32-51 region is a potential candidate for the anticancer therapy and its cell-penetrating capacity is an associated useful property. By the modification in the primary structure of L-2, a second-generation peptide (CIGB-552) was developed. However, the molecular mechanism underlying its cytotoxic activity remains partially unknown. In this study, it was shown that CIGB-552 increases the levels of COMMD1, a protein involved in copper homeostasis, sodium transport, and the NF-κB signaling pathway. We found that CIGB-552 induces ubiquitination of RelA and inhibits the antiapoptotic activity regulated by NF-κB, whereas the knockdown of COMMD1 blocks this effect. We also found that CIGB-552 decreases the antioxidant capacity and induces the peroxidation of proteins and lipids in the tumor cells. Altogether, this study provides new insights into the mechanism of action of the peptide CIGB-552, which could be relevant in the design of future anticancer therapies. Julio R. Fernández Massó, Brizaida Oliva Argüelles, Yelaine Tejeda, Soledad Astrada, Hilda Garay, Osvaldo Reyes, Livan Delgado-Roche, Mariela Bollati-Fogolín, and Maribel G. Vallespí Copyright © 2013 Julio R. Fernández Massó et al. All rights reserved. Ischemia Induces Release of Endogenous Amino Acids from the Cerebral Cortex and Cerebellum of Developing and Adult Mice Thu, 10 Jan 2013 11:19:42 +0000 http://www.hindawi.com/journals/jaa/2013/839036/ Ischemia enhanced release of endogenous neuroactive amino acids from cerebellar and cerebral cortical slices. More glutamate was released in adult than developing mice. Taurine release enhanced by K+ stimulation and ischemia was more than one magnitude greater than that of GABA or glutamate in the developing cerebral cortex and cerebellum, while in adults the releases were almost comparable. Aspartate release was prominently enhanced by both ischemia and K+ stimulation in the adult cerebral cortex. In the cerebellum K+ stimulation and ischemia evoked almost 10-fold greater GABA release in 3-month olds than in 7-day olds. The release of taurine increased severalfold in the cerebellum of 7-day-old mice in high-K+ media, whereas the K+-evoked effect was rather small in adults. In 3-month-old mice no effects of K+ stimulation or ischemia were seen in the release of aspartate, glycine, glutamine, alanine, serine, or threonine. The releases from the cerebral cortex and cerebellum were markedly different and also differed between developing and adult mice. In developing mice only the release of inhibitory taurine may be large enough to counteract the harmful effects of excitatory amino acids in ischemia in both cerebral cortex and cerebellum, in particular since at that age the release of glutamate and aspartate cannot be described as massive. Simo S. Oja and Pirjo Saransaari Copyright © 2013 Simo S. Oja and Pirjo Saransaari. All rights reserved. Cancer Treatment Using Peptides: Current Therapies and Future Prospects Thu, 20 Dec 2012 18:13:47 +0000 http://www.hindawi.com/journals/jaa/2012/967347/ This paper discusses the role of peptides in cancer therapy with special emphasis on peptide drugs which are already approved and those in clinical trials. The potential of peptides in cancer treatment is evident from a variety of different strategies that are available to address the progression of tumor growth and propagation of the disease. Use of peptides that can directly target cancer cells without affecting normal cells (targeted therapy) is evolving as an alternate strategy to conventional chemotherapy. Peptide can be utilized directly as a cytotoxic agent through various mechanisms or can act as a carrier of cytotoxic agents and radioisotopes by specifically targeting cancer cells. Peptide-based hormonal therapy has been extensively studied and utilized for the treatment of breast and prostate cancers. Tremendous amount of clinical data is currently available attesting to the efficiency of peptide-based cancer vaccines. Combination therapy is emerging as an important strategy to achieve synergistic effects in fighting cancer as a single method alone may not be efficient enough to yield positive results. Combining immunotherapy with conventional therapies such as radiation and chemotherapy or combining an anticancer peptide with a nonpeptidic cytotoxic drug is an example of this emerging field. Jyothi Thundimadathil Copyright © 2012 Jyothi Thundimadathil. All rights reserved.