TY - JOUR
T1 - Design of short membrane selective antimicrobial peptides containing tryptophan and arginine residues for improved activity, salt-resistance, and biocompatibility
AU - Saravanan, Rathi
AU - Li, Xiang
AU - Lim, Kaiyang
AU - Mohanram, Harini
AU - Peng, Li
AU - Mishra, Biswajit
AU - Basu, Anindya
AU - Lee, Jong Min
AU - Bhattacharjya, Surajit
AU - Leong, Susanna Su Jan
PY - 2014/1
Y1 - 2014/1
N2 - Antimicrobial peptides (AMPs) kill microbes by non-specific membrane permeabilization, making them ideal templates for designing novel peptide-based antibiotics that can combat multi-drug resistant pathogens. For maximum efficacy in vivo and in vitro, AMPs must be biocompatible, salt-tolerant and possess broad-spectrum antimicrobial activity. These attributes can be obtained by rational design of peptides guided by good understanding of peptide structure-function. Toward this end, this study investigates the influence of charge and hydrophobicity on the activity of tryptophan and arginine rich decamer peptides engineered from a salt resistant human β-defensin-28 variant. Mechanistic investigations of the decamers with detergents mimicking the composition of bacterial and mammalian membrane, reveal a correlation between improved antibacterial activity and the increase in tryptophan and positive residue content, while keeping hemolysis low. The potent antimicrobial activity and high cell membrane selective behavior of the two most active decamers, D5 and D6, are attributed to an optimum peptide charge to hydrophobic ratio bestowed by systematic arginine and tryptophan substitution. D5 and D6 show surface localization behavior with binding constants of 1.86×108 and 2.6×108M-1, respectively, as determined by isothermal calorimetry measurements. NMR derived structures of D5 and D6 in SDS detergent micelles revealed proximity of Trp and Arg residues in an extended structural scaffold. Such potential cation-π interactions may be critical in cell permeabilization of the AMPs. The fundamental characterization of the engineered decamers provided in this study improves the understanding of structure-activity relationship of short arginine tryptophan rich AMPs, which will pave the way for future de novo design of potent AMPs for therapeutic and biomedical applications.
AB - Antimicrobial peptides (AMPs) kill microbes by non-specific membrane permeabilization, making them ideal templates for designing novel peptide-based antibiotics that can combat multi-drug resistant pathogens. For maximum efficacy in vivo and in vitro, AMPs must be biocompatible, salt-tolerant and possess broad-spectrum antimicrobial activity. These attributes can be obtained by rational design of peptides guided by good understanding of peptide structure-function. Toward this end, this study investigates the influence of charge and hydrophobicity on the activity of tryptophan and arginine rich decamer peptides engineered from a salt resistant human β-defensin-28 variant. Mechanistic investigations of the decamers with detergents mimicking the composition of bacterial and mammalian membrane, reveal a correlation between improved antibacterial activity and the increase in tryptophan and positive residue content, while keeping hemolysis low. The potent antimicrobial activity and high cell membrane selective behavior of the two most active decamers, D5 and D6, are attributed to an optimum peptide charge to hydrophobic ratio bestowed by systematic arginine and tryptophan substitution. D5 and D6 show surface localization behavior with binding constants of 1.86×108 and 2.6×108M-1, respectively, as determined by isothermal calorimetry measurements. NMR derived structures of D5 and D6 in SDS detergent micelles revealed proximity of Trp and Arg residues in an extended structural scaffold. Such potential cation-π interactions may be critical in cell permeabilization of the AMPs. The fundamental characterization of the engineered decamers provided in this study improves the understanding of structure-activity relationship of short arginine tryptophan rich AMPs, which will pave the way for future de novo design of potent AMPs for therapeutic and biomedical applications.
KW - Antimicrobial peptide
KW - Membrane permeabilization
KW - Peptide engineering
KW - Structure-activity relationship, nuclear magnetic resonance
KW - Tryptophan arginine rich peptide
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U2 - 10.1002/bit.25003
DO - 10.1002/bit.25003
M3 - Article
C2 - 23860860
AN - SCOPUS:84888046119
SN - 0006-3592
VL - 111
SP - 37
EP - 49
JO - Biotechnology and Bioengineering
JF - Biotechnology and Bioengineering
IS - 1
ER -