Structural and Functional Aspects of Class A Carbapenemases

Area of Science:

• Microbiology
• Structural Biology
• Drug Discovery

Background:

• The rise of carbapenem-resistant gram-negative bacteria, including pan-drug resistant strains, poses a significant global public health challenge.
• Carbapenemases, enzymes that degrade carbapenems, threaten the efficacy of last-resort antibiotics, potentially reverting medicine to a pre-antibiotic era.
• Clinically significant carbapenemases include Ambler class B metallo-β-lactamases (MBLs) and Ambler class A and D serine-β-lactamases (SBLs).

Purpose of the Study:

• To investigate the structure-function relationships of Ambler class A carbapenemases.
• To identify structural factors influencing the hydrolytic activity and inhibition of these enzymes.
• To provide insights for the rational design of novel therapeutic agents against carbapenem-resistant bacteria.

Main Methods:

• Analysis of three-dimensional structures of class A carbapenemases in apo and complex forms.
• Site-directed mutagenesis studies to probe enzyme mechanisms.
• Comparative analysis of sequence identities, structural features, and inhibition profiles.

Main Results:

• Class A carbapenemases, despite low sequence identity, share conserved structural features and a common mechanism of action.
• Structural data and mutagenesis studies reveal key determinants of hydrolytic activity and inhibitor susceptibility.
• Understanding these structure-function relationships is crucial for predicting enzyme phenotypes.

Conclusions:

• Detailed structural and functional analysis of class A carbapenemases provides fundamental insights into antibiotic resistance mechanisms.
• These findings are essential for guiding the development of new drugs to combat infections caused by carbapenem-resistant gram-negative organisms.
• Targeting carbapenemase activity represents a promising strategy to overcome the challenge of multidrug-resistant bacterial infections.