Restricted Rotational Flexibility of the C5α-Methyl-Substituted Carbapenem NA-1-157 Leads to Potent Inhibition of the GES-5 Carbapenemase
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Carbapenem antibiotics are used as a last-resort treatment for infections caused by multidrug-resistant bacteria. The wide spread of carbapenemases in Gram-negative bacteria has severely compromised the utility of these drugs and represents a serious public health threat. To combat carbapenemase-mediated resistance, new antimicrobials and inhibitors of these enzymes are urgently needed. Here, we describe the interaction of the atypically C5α-methyl-substituted carbapenem, NA-1-157, with the GES-5 carbapenemase. MICs of this compound against Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii producing the enzyme were reduced 4–16-fold when compared to MICs of the commercial carbapenems, reaching clinically sensitive breakpoints. When NA-1-157 was combined with meropenem, a strong synergistic effect was observed. Kinetic and ESI-LC/MS studies demonstrated that NA-1-157 is a potent inhibitor of GES-5, with a high inactivation efficiency of (2.9 ± 0.9) × 10 5 M –1 s –1 . Acylation of GES-5 by NA-1-157 was biphasic, with the fast phase completing within seconds, and the slow phase taking several hours and likely proceeding through a reversible tetrahedral intermediate. Deacylation was extremely slow ( k 3 = (2.4 ± 0.3) × 10 –7 s –1 ), resulting in a residence time of 48 ± 6 days. MD simulation of the GES-5-meropenem and GES-5-NA-1-157 acyl-enzyme complexes revealed that the C5α-methyl group in NA-1-157 sterically restricts rotation of the 6α-hydroxyethyl group preventing ingress of the deacylating water into the vicinity of the scissile bond of the acyl-enzyme intermediate. These data demonstrate that NA-1-157 is a potent irreversible inhibitor of the GES-5 carbapenemase.
Source: ACS Infectious Diseases
Language: English
Subfield: Molecular Medicine
Domain: Life Sciences
Open Access status: green
Funders: U.S. Department of Energy, National Institutes of Health, Office of Science, Biotechnology and Biological Sciences Research Council, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases, Basic Energy Sciences, Biological and Environmental Research
Awards: G1229526393, G1265825722, G1286251239, G2302111672, G2371548206, G303061748, G315621713, G3174942240, G4581610328, G495301720, G498139845, G5208490932, G5471012614, G5570207115, G5706957992, G6550344761, G7283024673, G7396808078, G7863156295, G8382000481, Antibiotics Designed to Counter Resistant 21st Century Pathogens, G8925327636, A Synchrotron Radiation Structural Biology Resource, Carbapenemase-Stable Carbapenem Antibiotics for Treatment of Multidrug-Resistant Acinetobacter baumannii Infections, G911061179, G969889393
OpenAlex ID: W4393041749