Table 1: Data on structure and antimicrobial activities of the investigated peptides.

NameOrigin/molecular massAmino acid sequenceTotal net charge at pH 7/pH 5.6(a, e)Total hydrophobic ratio [%](a)No. of hydrophobic residues on molecule surface/all residues(a)Secondary structure IEP predictedAntimicrobial and hemolytic activities

E-5-KResidues 1–5 of α-lactalbumin/689 g/molH2N-EQLTK-COOH0/ca. 0(b)200/1Random coil or quasi-pure β-sheet(c) [26]6.1 [26]
6.9 [35]
G. + bacteria; Not fungicidal [26]

L-16-YResidues 164–179 of α-casein/2011.4 DaH2N-LKKISQRYQKFALPQY-COOH+4/+4310/5Random coil [35] or α-helix(c, e) [31, 35]10.5 [35]G. + and G. − bacteria; Slightly hemolytic [31]

N-23-T or Lactophoricin-I (LPcin-I)Residues 113–135 of bovine component-3 of proteose peptone (PP3)/2683 DaH2N-NTVKETIKYLKSLFSHAFEVVKT-COOH+2.1/+3399/9α-helix(c) [32], random in solutions and 50% helical content in LPC(d) and SDS(d) micelles [33], monomer in H2O [32]9.4 [33]
9.95(e)
Mostly against G. + bacteria,
not hemolytic [32]

Values predicted using the “APD2: Antimicrobial Peptide Predictor” software, available at http://aps.unmc.edu/AP/main.php [3].
According to the theoretical prediction of IEP of E-5-K (consistent with [26, 35]), this peptide should adopt a slightly positive charge at the used pH ca. 5.6; however, the penetration results (Figure 8) indicate a slight negative charge of E-5-K, under the experimental conditions.
Derived according to the secondary structure algorithm [31].
LPC denotes L-α-lysophosphatidylcholine, and SDS denotes sodium dodecyl sulphate.
The value is predicted using the “Peptide Property Calculator” of CS Bio Co. software available at http://pepcalc.com/ppc.php (used also in [35]).