Inhibition of bacterial growth by peptide-peptide nucleic acid targeted to domainII of 23SrRNA

Objective To study the inhibition of bacterial growth by peptide-peptide nucleic acid(PNA)(G1138) targeted to domain Ⅱ of 23SrRNA.Methods The bactericidal effect of antibacterial peptide-PNA(G1138) conjugates on Escherichia coli(E.coli) DH5α was observed by turbidity analysis and further examined by colony-forming units.Results Peptide-PNA(G1138) targeted to domain Ⅱ of 23SrRNA could inhibit bacterial growth in a dose-and sequence-dependent manner,but the minimum inhibitory concentration(MIC) of peptide-PNA(G1138) against E.coli was significantly higher than that of tetracycline,the bactericidal effect was less effective than that of tetracycline.Their MICs were 10 and 4 μmol/L respectively.Conclusions Peptide-PNA(G1138) at 10 μmol/L can inhibit E.coli DH5α growth,but the inhibitory effect of peptide-PNA(G1138) is not satisfactory in comparison with tetracycline and other PNAs targeted to domain V of 23SrRNA.To screen more effective cell-permeabilizing peptide and to improve the bactericidal effect of peptide-PNA(G1138) are the aims of further research.