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The Scientific World Journal
Volume 2015, Article ID 740815, 8 pages
http://dx.doi.org/10.1155/2015/740815
Research Article

Discovery of Specific Inhibitors for Intestinal E. coli  β-Glucuronidase through In Silico Virtual Screening

1Graduate Institute of Pharmacognosy, Taipei Medical University, 252 Wu Hsing Street, Taipei 11031, Taiwan
2Institute of Biomedical Sciences, Academia Sinica, 128 Section 2, Academia Road, Nankang, Taipei 11529, Taiwan
3Institute of Biomedical Science, 70 Lienhai Road, Kaohsiung 80424, National Sun Yat-Sen University, Taiwan
4Department of Pharmacy, Chia Nan University of Pharmacy and Science, 60 Section 1, Erh-Ren Road, Tainan 71710, Taiwan
5Department of Biomedical and Environmental Biology, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan
6Graduate Institute of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan
7Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan
8School of Pharmacy, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan

Received 15 August 2014; Accepted 27 August 2014

Academic Editor: Li-Yeh Chuang

Copyright © 2015 Ta-Chun Cheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Supplementary Material

Fifty-nine candidate compounds were acquired from the initial virtually screening which was designed to target the bacterial loop of eβG and its active site. The docking energy scores of 59 candidate compounds measured by the DOCK program are -43 to -55 kcal/mol. (Table S1) The candidate compounds were purchased from SPECS (Zoetermeer, The Netherlands). Each candidate was rovided as a solid power and dissolved in 100% DMSO (Sigma-Aldrich, MO, USA) to 10 mM as stock. Candidates were screening for their inhibition specificity of eβG verse hβG, which were conducted at pH 7.3 or pH 5.4 in triplicate, respectively. 40 µL purified βG was treated with 10 µL compound solution at 37 °C for 30 min, and sequentially incubated with 50 µL of pNPG (Sigma-Aldrich) at 37 °C for 30 min. Reactions were quenched with 5 µL of 2 N sodium hydroxide (Sigma-Aldrich). Each reaction consisted of 3.75 ng purified βG, 50 µM compound, and 5 mM pNPG in PBS containing 10% DMSO and 0.05% BSA (Sigma-Aldrich). βG-activities were measured by color development of pNP detected on a microplate reader at OD 405 nm. Results are displayed as percent of βG activity compared with the untreated control. The result showed that all the 59 candidate compounds displayed selective inhibition against eβG activity. Especially, the inhibiting ability against eβG activity was >95% in 7 candidates of eβG specific inhibitors (Table S1).

  1. Supplementary Material