Analogies and surprising differences between recombinant nitric oxide synthase-like proteins from Staphylococcus aureus and Bacillus anthracis in their interactions with l-arginine analogs and iron ligands.
Analogies and surprising differences between recombinant nitric oxide synthase-like proteins from Staphylococcus aureus and Bacillus anthracis in their interactions with l-arginine analogs and iron ligands.
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DOI：
10.1016/j.jinorgbio.2006.09.017
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发表时间：
2006-12
影响因子：
3.9
通讯作者：
Isabelle Salard;E. Mercey;E. Rekka;J. Boucher;P. Nioche;I. Mikula;P. Martásek;C. Raman;D. Mansuy
中科院分区：
文献类型：
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作者：
Isabelle Salard;E. Mercey;E. Rekka;J. Boucher;P. Nioche;I. Mikula;P. Martásek;C. Raman;D. Mansuy
最近基因组测序显示细菌中存在编码一氧化氮合酶（NOS）样蛋白的基因。这些蛋白质的作用尚不清楚。用紫外-可见光谱法研究了一系列L-精氨酸（l-arg）类似物和铁配体与两种重组一氧化氮合酶样蛋白（saNOS和巴诺斯）的相互作用。SaNOS和巴诺斯在其铁的天然状态，以及它们的复合物与L-Arg类似物和各种配体，表现出光谱特性高度相似的血红素-硫醇盐蛋白质，如细胞色素P450和NOS的相应的复合物。然而，saNOS与巴诺斯在三个主要特性方面有很大不同：（i）天然saNOS主要存在于六配位的低自旋铁状态下，而天然巴诺斯主要是高自旋的，（ii）四氢生物蝶呤（H4 B）或H4 B类似物的加入导致l-arg对saNOS而不是巴诺斯的亲和力增加，和（iii）saNOS Fe II，与巴诺斯相反，结合相对大体积的配体，例如亚硝基烷烃和叔丁基异氰。因此，saNOS表现出与不含H4 B的诱导型NOS（iNOSoxy）的加氧酶结构域的性质非常相似的性质，如对于不含H4 B的NOSoxy样蛋白所预期的。相比之下，巴诺斯的性质看起来像含H4 B的iNOSoxy的性质，这对于不含H4 B的NOS样蛋白质来说是出乎意料的。巴诺斯这些令人惊讶的特性的起源仍有待确定。
Genome sequencing has recently shown the presence of genes coding for NO-synthase (NOS)-like proteins in bacteria. The roles of these proteins remain unclear. The interactions of a series of l-arginine (l-arg) analogs and iron ligands with two recombinant NOS-like proteins from Staphylococcus aureus (saNOS) and Bacillus anthracis (baNOS) have been studied by UV–visible spectroscopy. SaNOS and baNOS in their ferric native state, as well as their complexes with l-arg analogs and with various ligands, exhibit spectral characteristics highly similar to the corresponding complexes of heme-thiolate proteins such as cytochromes P450 and NOSs. However, saNOS greatly differs from baNOS at the level of three main properties: (i) native saNOS mainly exists under an hexacoordinated low-spin ferric state whereas native baNOS is mainly high-spin, (ii) the addition of tetrahydrobiopterin (H4B) or H4B analogs leads to an increase of the affinity of l-arg for saNOS but not for baNOS, and (iii) saNOS FeII, contrary to baNOS, binds relatively bulky ligands such as nitrosoalkanes and tert-butylisocyanide. Thus, saNOS exhibits properties very similar to those of the oxygenase domain of inducible NOS (iNOSoxy) not containing H4B, as expected for a NOSoxy-like protein that does not contain H4B. By contrast, the properties of baNOS which look like those of H4B-containing iNOSoxyare unexpected for a NOS-like protein not containing H4B. The origin of these surprising properties of baNOS remains to be determined.