Overexpression and Characterization of Metallo-β-lactamase from Klebsilla pneumoniae: NDM-1

Since bacterial pathogens are able to develop resistance after exposure to antibiotics, antibiotic resistance is a serious problem in medicine. Resistance to antibiotics occurs by the production of β-lactamases, which cleave the β-lactam bond present in common antibiotics such as penicillin. This study focuses on the overexpression and characterization of the New Delhi metallo-β-lactamase enzyme by conducting studies on the dependence of ionic strength, buffer concentration, and pH on the β-lactamase-catalyzed hydrolysis of Penicillin G. Results showed that NDM-1 was successfully purified. The effect of ionic strength on MOPS buffer showed an initial decrease and then an increase in the kcat/Km, while phosphate buffer showed an increase and then decrease in the kcat/Km value. In the case of buffer effect, MOPS and phosphate buffer showed a strong decrease in kcat/Km as buffer concentration increased. The pH studies showed some scattering data points, suggesting that the protein is unable to endure some acid/base conditions.