Molecular Characterization of a Novel Family VIII Esterase with β-Lactamase Activity (PsEstA) from Paenibacillus sp.

Sena Kwon,T Doohun Kim,Young-Ok Kim,Kyeong Kyu Kim,Wanki Yoo

doi:10.3390/biom9120786

Abstract

Molecular information about family VIII esterases, which have similarities with class C β-lactamases and penicillin-binding proteins, remains largely unknown. In this study, a novel family VIII esterase with β-lactamase activity (PsEstA) from Paenibacillus sp. was characterized using several biochemical and biophysical methods. PsEstA was effective on a broad range of substrates including tertiary butyl acetate, glyceryl tributyrate, glucose pentaacetate, olive oil, and p-nitrophenyl esters. Additionally, PsEstA hydrolyzed nitrocefin, cefotaxime, and 7-aminocephalosporanic acid. Interestingly, two forms of immobilized PsEstA (CLEAs-PsEstA and mCLEAs-PsEstA) showed high recycling property and enhanced stability, but hybrid nanoflowers (hNFs) of PsEstA require improvement. This study provides a molecular understanding of substrate specificities, catalytic regulation, and immobilization of PsEstA, which can be efficiently used in biotechnological applications.

Highlights

Bacterial β-lactamases hydrolyze chemical compounds containing a β-lactam ring and are the primary cause of bacterial resistance against different classes of β-lactam antibiotics
Classes A, C, and D hydrolyze their substrates through the formation of an acyl-enzyme with a catalytic serine, whereas class B utilizes a zinc ion to facilitate a hydrolytic reaction
Among β-lactamases, class C enzymes are of high importance, because they pose significant threats for antibiotic treatments due to their occurrence in many gram-negative pathogens, such as Enterobacteriaceae and Pseudomonas spp. [5,6]

Summary

Introduction

Bacterial β-lactamases hydrolyze chemical compounds containing a β-lactam ring and are the primary cause of bacterial resistance against different classes of β-lactam antibiotics. The production of one or more types of β-lactamase is the most effective strategy through which clinically important gram-negative bacteria effectively hydrolyze the β-lactam rings of antibiotics, such as penicillins, cephalosporins, or carbapenems [1,2,3]. Among β-lactamases, class C enzymes are of high importance, because they pose significant threats for antibiotic treatments due to their occurrence in many gram-negative pathogens, such as Enterobacteriaceae and Pseudomonas spp. Class C β-lactamases play a role in the resistance of these pathogens to cephalosporins, cephamycins, and carbapenems, and are not inhibited by clavulanic acid [7,8]. The molecular structure of class C β-lactamases consists of two domains of different sizes

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Conclusion