A reaction involving protein sulfhydryl groups, a bound spin-label, and K3Fe(CN)6 as a probe of sulfhydryl proximity in myosin.
A reaction involving protein sulfhydryl groups, a bound spin-label, and K3Fe(CN)6 as a probe of sulfhydryl proximity in myosin.
复制标题
涉及蛋白质硫氢基、结合的自旋标记和作为肌球蛋白中硫氢基邻近度探针的 K3Fe(CN)6 的反应。
DOI：
10.1021/bi00542a006
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发表时间：
1980
期刊：
影响因子：
2.9
通讯作者：
J. Seidel
中科院分区：
文献类型：
--
作者：
P. Graceffa;J. Seidel
Philip Graceffa** 和 John C. Seidel 摘要：用碘乙酰胺自旋标签标记的肌球蛋白的 EPR 谱显示了与弱固定化标签和强固定化标签相对应的成分。用 K3Fe (CN) 3 处理该肌球蛋白后，涉及自旋标记的硝基氧基团 Fe (CN) 63~ 和蛋白质的巯基的化学反应导致选择性破坏弱固定的光谱成分，而不损失 ATP 酶活性。巯基参与该反应的事实表明，K3Fe (CN) 6 仅在含硫醇化合物存在的情况下才会破坏自旋标记的电子顺磁共振（EPR）信号，并且如果巯基被阻断，信号也不会丢失。在 MgADP 存在的情况下，强固定组分（归因于与肌球蛋白的 SH-1 硫醇结合的标记）和弱固定组分
Philip Graceffa** and John C. Seidel abstract: The EPR spectrum of myosin labeled with an iodoacetamide spin-label shows componentscorresponding to weakly and to strongly immobilized labels. Upon treatment of this myosin wiith K3Fe (CN) 3, a chemical reaction involving the nitroxide group of the spin-label, Fe (CN) 63~, and a sulfhydryl group of the protein results in the selective destruction of the weakly immobilized spectral component without loss of ATPase activity. The involvement of a sulfhydryl group in this reaction is indicated by the fact that K3Fe (CN) 6 de-stroys the electron paramagnetic resonance(EPR) signal of a spin-label only in thepresence of a thiol-containing com-pound and that the signal is not lost if the sulfhydryl group is blocked. In the presence of MgADP, both the strongly immobilized component, attributable to labels bound to the SH-1 thiols of myosin, and the weakly immobilized component