Gramicidin A is hydrolyzed by a D-stereospecific peptidase produced by Bacillus anthracis
article
Previously we described the discovery of a Bacillus spp. specific peptidase activity related to Dstereospecific peptidases (DSPs). The peptidase showed a strong preference for D-leucine and D-valine amino acids. These amino acids are present in the structure of the non-ribosomal peptide (NRP) antibiotics gramicidin A, B and C and polymyxin E. To examine if the Bacillus spp. DSP-related peptidase can hydrolyze these NRPs, the effect of gramicidin A and C and polymyxin E on peptidase activity in Bacillus anthracis culture supernatant was monitored. It was found that both gramicidins inhibited the DSPrelated activity in a competitive manner. MALDI-TOF analysis revealed that upon incubation with B. anthracis culture supernatant gramicidin A hydrolyzation products appeared. This study shows that the Bacillus spp. specific DSP-like peptidase was potentially produced by the bacteria to gain intrinsic resistance against NRP antibiotics. These results are of utmost importance in research towards antimicrobial resistance, whereas transfer of DSP-related activity to other clinically relevant pathogens can be a serious threat to human health.
TNO Identifier
967065
ISSN
1758-2229
Source
Environmental Microbiology Reports, 14(4), pp. 570-576.
Pages
570-576