Isolation, Purification and Characterization of L,D-transpeptidase 2 from Mycobacterium tuberculosis
Isolation, Purification and Characterization of L,D-transpeptidase 2 from Mycobacterium tuberculosis
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DOI：
10.32607/20758251-2019-11-1-23-28
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发表时间：
2019-01-01
期刊：
影响因子：
2
通讯作者：
Svedas, V. K.
中科院分区：
文献类型：
--
作者：
Baldin, S. M.;Shcherbakova, T. A.;Svedas, V. K.
来自结核分枝杆菌的 L,D-转肽酶 2 在病原体细胞壁中非经典 3-3 肽聚糖交联的形成中发挥着关键作用，使其对多种青霉素抗生素产生耐药性。本研究对结核分枝杆菌重组 L,D-转肽酶 2 的培养、分离和纯化条件进行了优化。催化半胱氨酸Cys354的游离SH基团的氧化是导致酶失活的重要因素，这种情况发生在酶制剂的表达和储存过程中。测定纯化的L,D-转肽酶2和缺失A结构域的L,D-转肽酶2的生化特性；评估了酶催化硝头孢芬转化的动力学常数。
L,D-transpeptidase 2 from Mycobacterium tuberculosis plays a key role in the formation of nonclassical 3-3 peptidoglycan cross-links in a pathogen's cell wall making it resistant to a broad range of penicillin antibiotics. The conditions of cultivation, isolation, and purification of recombinant L,D-transpeptidase 2 from M. tuberculosis have been optimized in this study. Oxidation of the free SH groups of catalytic cysteine Cys354 is an important factor causing the inactivation of the enzyme, which occurs during both the expression and storage of enzyme preparations. The biochemical characteristics of purified L,D-transpeptidase 2 and L, D-transpeptidase 2 lacking domain A were determined; the kinetic constants of enzyme-catalyzed nitrocefin transformation were evaluated.