Chartier François J M, Couture Manon
Département de Biochimie et de Microbiologie and the Centre de Recherche sur la Fonction, la Structure, et l'Ingénierie des Protéines, Université Laval, Quebec City, Quebec G1K 7P4, Canada.
J Biol Chem. 2007 Jul 20;282(29):20877-86. doi: 10.1074/jbc.M701800200. Epub 2007 May 30.
We report the characterization by resonance Raman spectroscopy of the oxygenated complex (Fe(II)O(2)) of nitric-oxide synthases of Staphylococcus aureus (saNOS) and Bacillus subtilis (bsNOS) saturated with N(omega)-hydroxy-l-arginine. The frequencies of the nu(Fe-O) and nu(O-O) modes were 530 and 1135 cm(-), respectively, in both the presence and absence of tetrahydrobiopterin. On the basis of a comparison of these frequencies with those of saNOS and bsNOS saturated with l-arginine (nu(Fe-O) at 517 cm(-1) and nu(O-O) at 1123 cm(-1)) and those of substrate-free saNOS (nu(Fe-O) at 517 and nu(O-O) at 1135 cm(-1)) (Chartier, F. J. M., Blais, S. P., and Couture, M. (2006) J. Biol. Chem. 281, 9953-9962), we propose two models that account for the frequency shift of nu(Fe-O) (but not nu(O-O)) upon N(omega)-hydroxy-l-arginine binding as well as the frequency shift of nu(O-O) (but not nu(Fe-O)) upon l-arginine binding. The implications of these substrate-specific interactions with respect to catalysis by NOSs are discussed.
我们报道了通过共振拉曼光谱对金黄色葡萄球菌（saNOS）和枯草芽孢杆菌（bsNOS）一氧化氮合酶的含氧复合物（Fe(II)O₂）进行的表征，该复合物用N(ω)-羟基-L-精氨酸饱和。无论是否存在四氢生物蝶呤，ν(Fe-O)和ν(O-O)模式的频率分别为530和1135 cm⁻¹。基于将这些频率与用L-精氨酸饱和的saNOS和bsNOS的频率（ν(Fe-O)为517 cm⁻¹，ν(O-O)为1123 cm⁻¹）以及无底物的saNOS的频率（ν(Fe-O)为517，ν(O-O)为1135 cm⁻¹）进行比较（沙蒂埃，F. J. M.，布莱斯，S. P.，和库蒂尔，M.（2006年）《生物化学杂志》281，9953 - 9962），我们提出了两个模型，这两个模型解释了N(ω)-羟基-L-精氨酸结合时ν(Fe-O)（而非ν(O-O)）的频率变化以及L-精氨酸结合时ν(O-O)（而非ν(Fe-O)）的频率变化。讨论了这些底物特异性相互作用对一氧化氮合酶催化作用的影响。
