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Characterization of the extended substrate spectrum of the class A β-lactamase CESS-1 from Stenotrophomonas sp. and structure-based investigation into its substrate preference
- Title
- Characterization of the extended substrate spectrum of the class A β-lactamase CESS-1 from Stenotrophomonas sp. and structure-based investigation into its substrate preference
- Authors
- Jeong; Bo-Gyeong; Kim; Myeong-Yeon; Chang-Sook; Do; Hackwon; Hwang; Jisub; Lee; Jun Hyuck; Cha; Sun-Shin
- Ewha Authors
- 차선신
- SCOPUS Author ID
- 차선신
![scopus](/images/layout/icon2.png)
- Issue Date
- 2024
- Journal Title
- International Journal of Antimicrobial Agents
- ISSN
- 9248-8579
- Citation
- International Journal of Antimicrobial Agents vol. 63, no. 6
- Keywords
- Acyl-enzyme complexes; Crystal structure; Extended substrate spectrum class A β-lactamase; Steady-state enzyme kinetics; Stenotrophomonas sp.
- Indexed
- SCIE; SCOPUS
![scopus](/images/layout/scopus2.gif)
- Document Type
- Article
- Abstract
- Objectives: Stenotrophomonas spp. intrinsically resistant to many β-lactam antibiotics are found throughout the environment. CESS-1 identified in Stenotrophomonas sp. KCTC 12332 is an uncharacterized class A β-lactamase. The goal of this study was to reveal biochemical and structural characteristics of CESS-1. Methods: The hydrolytic activities of CESS-1 towards penicillins (penicillin G and ampicillin), cephalosporins (cephalexin, cefaclor, and cefotaxime), and carbapenems (imipenem and meropenem) was spectrophotometrically monitored. Structural information on E166Q mutants of CESS-1 acylated by cefaclor, cephalexin, or ampicillin were determined by X-ray crystallography. Results: CESS-1 displayed hydrolytic activities toward penicillins and cephalosporins, with negligible activity toward carbapenems. Although cefaclor, cephalexin, and ampicillin have similar structures with identical R1 side chains, the catalytic parameters of CESS-1 toward them were distinct. The kcat values for cefaclor, cephalexin, and ampicillin were 1249.6 s-1, 204.3 s-1, and 69.8 s-1, respectively, with the accompanying KM values of 287.6 μM, 236.7 μM, and 28.8 μM, respectively. Conclusions: CESS-1 was able to discriminate between cefaclor and cephalexin with a single structural difference at C3 position: –Cl (cefaclor) and –CH3 (cephalexin). Structural comparisons among three E166Q mutants of CESS-1 acylated by cefaclor, cephalexin, or ampicillin, revealed that cooperative positional changes in the R1 side chain of substrates and their interaction with the β5-β6 loop affect the distance between Asn170 and the deacylating water at the acyl-enzyme intermediate state. This is directly associated with the differential hydrolytic activities of CESS-1 toward the three structurally similar β-lactam antibiotics. © 2024 Elsevier Ltd and International Society of Antimicrobial Chemotherapy
- DOI
- 10.1016/j.ijantimicag.2024.107171
- Appears in Collections:
- 자연과학대학 > 화학·나노과학전공 > Journal papers
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