番茄（Solanum lycopersicum）新型甲硫氨酸亚砜还原酶 A 的特性及其在大肠杆菌中的保护作用。
Characterization of a novel methionine sulfoxide reductase A from tomato (Solanum lycopersicum ), and its protecting role in Escherichia coli.
机构信息
Department of Mechanical Engineering, College of Biomedical Science, Kangwon National University, Samcheok 245-711, Korea.
出版信息
BMB Rep. 2011 Dec;44(12):805-10. doi: 10.5483/bmbrep.2011.44.12.805.
Methionine sulfoxide reductase A (MSRA) is a ubiquitous enzyme that has been demonstrated to reduce the S enantiomer of methionine sulfoxide (MetSO) to methionine (Met) and can protect cells against oxidative damage. In this study, we isolated a novel MSRA (SlMSRA2) from Micro-Tom (Solanum lycopersicum L. cv. Micro-Tom) and characterized it by subcloning the coding sequence into a pET expression system. Purified recombinant protein was assayed by HPLC after expression and refolding. This analysis revealed the absolute specificity for methionine-S-sulfoxide and the enzyme was able to convert both free and protein-bound MetSO to Met in the presence of DTT. In addition, the optimal pH, appropriate temperature, and Km and Kcat values for MSRA2 were observed as 8.5, 25oC, 352 ± 25 μM, and 0.066 ± 0.009 S(-1), respectively. Disk inhibition and growth rate assays indicated that SlMSRA2 may play an essential function in protecting E. coli against oxidative damage.
甲硫氨酸亚砜还原酶 A（MSRA）是一种普遍存在的酶，已被证明可以将甲硫氨酸亚砜（MetSO）的 S 对映体还原为甲硫氨酸（Met），并可以保护细胞免受氧化损伤。在这项研究中，我们从 Micro-Tom（Solanum lycopersicum L. cv. Micro-Tom）中分离出一种新型 MSRA（SlMSRA2），并通过将其编码序列亚克隆到 pET 表达系统中来对其进行了表征。表达和重折叠后，通过 HPLC 对纯化的重组蛋白进行了测定。该分析表明该酶对甲硫氨酸-S-亚砜具有绝对特异性，并且在 DTT 的存在下，该酶能够将游离和结合在蛋白质上的 MetSO 均转化为 Met。此外，观察到 MSRA2 的最佳 pH 值、适当的温度、Km 和 Kcat 值分别为 8.5、25°C、352±25 μM 和 0.066±0.009 s-1。圆盘抑制和生长速率测定表明，SlMSRA2 可能在保护大肠杆菌免受氧化损伤方面发挥重要作用。
Zotero 插件