Int J Oral Biol.  2014 Dec;39(4):169-176. 10.11620/IJOB.2014.39.4.169.

Identification of Antimicrobial Peptide Hexamers against Oral Pathogens through Rapid Screening of a Synthetic Combinatorial Peptide Library

• Song JS
• Cho KJ
• Kim J
• Kim JH

• KMID: 2170784
• DOI: http://doi.org/10.11620/IJOB.2014.39.4.169

Abstract

A positional scanning synthetic peptide combinatorial library (PS-SCL) was screened in order to identify antimicrobial peptides against the cariogenic oral bacteria, Streptococcus mutans. Activity against Streptococcus gordonii and Aggregatibacter actinomycetemcomitans was also examined. The library was comprised of six sub-libraries with the format O(1-6)XXXXX-NH2, where O represents one of 19 amino acids (excluding cysteine) and X represents equimolar mixture of these. Each sub-library was tested for antimicrobial activity against S. mutans and evaluated for antimicrobial activity against S. gordonii and A. actinomycetemcomitans. The effect of peptides was observed using transmission electron microscopy (TEM). Two semi-mixture peptides, RXXXXN-NH2 (pep-1) and WXXXXN-NH2 (pep-2), and one positioned peptide, RRRWRN-NH2 (pep-3), were identified. Pep-1 and pep-2 showed significant antimicrobial activity against Gram positive bacteria (S. mutans and S. gordonii), but not against Gram negative bacteria (A. actinomycetemcomitans). However, pep-3 showed very low antimicrobial activity against all three bacteria. Pep-3 did not form an amphiphilic alpha-helix, which is a required structure for most antimicrobial peptides. Pep-1 and pep-2 were able to disrupt the membrane of S. mutans. Small libraries of biochemically-constrained peptides can be used to generate antimicrobial peptides against S. mutans and other oral microbes. Peptides derived from such libraries may be candidate antimicrobial agents for the treatment of oral microorganisms.

Keyword

synthetic antimicrobial peptides; Streptococcus mutans; oral pathogens; helical wheel; membrane disruption

MeSH Terms

Aggregatibacter actinomycetemcomitans
Amino Acids
Anti-Infective Agents
Bacteria
Gram-Negative Bacteria
Gram-Positive Bacteria
Mass Screening*
Membranes
Microscopy, Electron, Transmission
Peptide Library*
Peptides
Streptococcus gordonii
Streptococcus mutans
Amino Acids
Anti-Infective Agents
Peptide Library
Peptides