2017 Volume 36 Issue 2 Pages 65-72
Penicillin-binding proteins (PBPs) are responsible for peptidoglycan synthesis. By using biotinylated ampicillin, we detected PBPs of Lactobacillus paracasei strains. Ten PBPs were identified, 7 of which had apparent molecular sizes similar to those of Escherichia coli. In the presence of cholate, strain NRIC 0625 showed an elongated shape, and its putative PBP3 showed cholate-sensitive penicillin-binding activity. Furthermore, this strain was highly sensitive to cefalexin, which is known to inhibit cell division by inactivating PBP3. These results suggest that the septum synthetase PBP3 of lactic acid bacteria can be one of the targets of intestinal bile acid.