Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, UMR 8601 CNRS, Paris, France.
J Inorg Biochem. 2012 Jan;106(1):164-71. doi: 10.1016/j.jinorgbio.2011.10.003. Epub 2011 Oct 8.
Genome sequencing has shown the presence of genes coding for NO-synthase (NOS)-like proteins in bacteria. The roles and properties of these proteins remain unclear. UV-visible spectroscopy was used to characterize the recombinant NOS-like protein from Bacillus subtilis (bsNOS) in its ferric and ferrous states in the presence of various Fe(III)- and Fe(II)-heme-ligands and of a series of L-arginine (L-arg) analogs. BsNOS exhibited several spectroscopic and binding properties in common with Bacillus anthracis NOS (baNOS) that were clearly different from those of tetrahydrobiopterin (H4B)-free mammalian NOS oxygenase domains (mNOS(oxys)) and of Staphylococcus aureus NOS (saNOS). Interestingly, bsNOS and baNOS that do not contain H4B exhibited properties much closer to those of H4B-containing mNOS(oxys). Moreover, bsNOS was found to efficiently catalyze the oxidation of L-arginine into L-citrulline by H(2)O(2), whereas H4B-free mNOS(oxys) exhibited low activities for this reaction.
基因组测序表明，在细菌中存在编码一氧化氮合酶（NOS）样蛋白的基因。这些蛋白质的作用和性质尚不清楚。本文采用紫外可见光谱法，在各种 Fe（III）和 Fe（II）血红素配体以及一系列 L-精氨酸（L-arg）类似物的存在下，对枯草芽孢杆菌（bsNOS）的重组 NOS 样蛋白进行了表征，观察其处于三价铁和二价铁状态时的结构特征。bsNOS 表现出与炭疽杆菌 NOS（baNOS）共同的几种光谱学和结合特性，与不含四氢生物蝶呤（H4B）的哺乳动物 NOS 氧化酶结构域（mNOS（oxys））和金黄色葡萄球菌 NOS（saNOS）明显不同。有趣的是，不含 H4B 的 bsNOS 和 baNOS 表现出与含有 H4B 的 mNOS（oxys）更为接近的特性。此外，研究发现 bsNOS 能有效地催化 H2O2 将 L-精氨酸氧化为 L-瓜氨酸，而不含 H4B 的 mNOS（oxys）对此反应的活性较低。
