The structure of formaldehyde-inhibited xanthine oxidase determined by 35 GHz 2H ENDOR spectroscopy.
The structure of formaldehyde-inhibited xanthine oxidase determined by 35 GHz 2H ENDOR spectroscopy.
复制标题
通过 35 GHz 2H ENDOR 光谱测定甲醛抑制的黄嘌呤氧化酶的结构。
DOI：
10.1021/ja106432h
复制
发表时间：
2010
影响因子：
15
通讯作者：
Hoffman,BrianM
中科院分区：
文献类型：
--
作者：
Shanmugam,Muralidharan;Zhang,Bo;McNaughton,RebeccaL;Kinney,RAdam;Hille,Russ;Hoffman,BrianM
甲醛抑制黄嘌呤氧化酶(I)的Mo(V)状态已经被研究了四十年，但还没有证明可以明确区分这种形式的几种结构。13c与CH2O之间独特的大各向同性超精细耦合导致了活性位点ofI的直接Mo - C键的有趣建议。这一建议得到了最近对醛氧化还原酶（黄嘌呤氧化酶家族的一员）的乙二醇和甘油抑制形式的晶体结构的支持。H2O/D2O缓冲液中（C1,2H2O）的1H和2h ENDOR光谱现已明确地揭示了其活性位点结构含有Mo(V)的CH2O加合物，其形式为四元环，S和O将C与Mo连接，并排除了直接Mo - C键的可能性。密度泛函理论计算与这一结论一致。我们将大的13c耦合解释为“跨环超精细相互作用”的结果。
The formaldehyde-inhibited Mo(V) state of xanthine oxidase (I) has been studied for four decades, yet it has not proven possible to distinguish unequivocally among the several structures proposed for this form. The uniquely large isotropic hyperfine coupling for13C from CH2O led to the intriguing suggestion of a direct Mo−C bond for the active site ofI. This suggestion was supported by the recent crystal structures of glycol- and glycerol-inhibited forms of aldehyde oxidoreductase, a member of the xanthine oxidase family.1H and2H ENDOR spectra ofI(C1,2H2O) in H2O/D2O buffer now have unambiguously revealed that the active-site structure ofIcontains a CH2O adduct of Mo(V) in the form of a four-membered ring with S and O linking the C to Mo and have ruled out a direct Mo−C bond. Density functional theory computations are consistent with this conclusion. We interpret the large13C coupling as resulting from a “transannular hyperfine interaction”.