Experimental studies have shown that the affinity of NDM-17 (V88L, M154L, and E170K) for all β-lactams is significantly higher than that of NDM-5 (V88L and M154L), and the increase in its catalytic activity may be related to the novel substitution of E170K.
V88L generated a destabilized effect on NDM-24. The V88L substitution occurred in the β-strand and low β-sheet content in the secondary structure, as evidenced by the CD analysis data.
Sequencing analyses of blaNDM region of the plasmid DNA determined two types of variants viz., NDM-1 (n = 3) and NDM-5 (n = 2). Notably, NDM-5 variants harbored V88L and M154L mutations, which are known to increase the fitness of NDM-5 variant towards host immune system and zinc starvation.
Highlights. •. blaNDM gene was detected in five E. coli isolates, with three of them being NDM-1 and two of them being NDM-5. •. The NDM-5 variants were found harbouring V88L and M154L mutations. •. The NDM variants were found harboring other antibiotic resistance markers, plasmid replicons and virulence genes. •.
Deciphering the Role of V88L Substitution in NDM-24 metallo-β-lactamase Zhihai Liua, b, Alessandra Piccirillic, Dejun Liub, Wan Lib, Yang Wangb and Jianzhong Shenb,* a Agricultural Bio-pharmaceutical Laboratory, College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, China
The V88L substitution occurred in the β-strand and low β-sheet content in the secondary structure, as evidenced by the CD analysis data. In conclusion, the V88L substitution increases the enzyme activity and decreases the protein stability.