Linear analogues of human beta-defensin 3: concepts for design of antimicrobial peptides with reduced cytotoxicity to mammalian cells.
A series of engineered linear analogues [coded as F6, W6, Y6, A6, S6 and C(Acm)6] were modeled, designed, synthesized and structurally characterized by mass spectra, circular dichroism, hydrophobicity analysis and molecular modeling. We have screened antimicrobial activity, hemolysis to rabbit erythrocytes, and cytotoxicity to human conjunctival epithelial cells. No significant hemolytic effect was observed for hBD3 or from five of the six analogues [F6, Y6, A6, S6 and C(Acm)6] over the range of 3-100 microg mL(-1). The six linear analogues have reduced cytotoxicity to human conjunctival epithelial cells over the range of 6-100 microg mL(-1) compared to hBD3. By tuning the overall hydrophobicity of linear hBD3 analogues, reduced cytotoxicity and hemolysis were obtained while preserving the antimicrobial properties. The decreased cytotoxicity of the linear analogues is suggested to be structurally related to the removal of disulfide bridges, and the flexible structure of the linear forms, which seem to be associated with loss of secondary structure. These results suggest a new approach for guiding the design of new linear analogues of defensin peptides with strong antibiotic properties and reduced cytotoxicity to mammalian cells.
Liu
Shouping
S
Singapore Eye Research Institute, 11 Third Hospital Avenue, #06-00, Singapore 16875, Singapore.
Zhou
Lei
L
Li
Jing
J
Suresh
Anita
A
Verma
Chandra
C
Foo
Yong Hwee
YH
Yap
Eric P H
EP
Tan
Donald T H
DT
Beuerman
Roger W
RW
D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003228:Conjunctiva / Q000166:cytology; D003545:Cysteine / Q000737:chemistry; D015195:Drug Design; D004847:Epithelial Cells / Q000187:drug effects; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011817:Rabbits; D023083:beta-Defensins / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity
D000890:Anti-Infective Agents; C422950:DEFB103A protein, human; D023083:beta-Defensins; D003545:Cysteine