Gregory M R, Daniel W E, Hiskey R G
Biochemistry. 1978 May 16;17(10):2025-30. doi: 10.1021/bi00603a035.
3-SLHis-105-RNase A is an active derivative of ribonuclease A (RNase A) spin-labeled at the 3 position of the imidazole ring of histidine-105. The spin-labeled enzyme has been modified by urea denaturation, reduction, reduction-carboxymethylation, performic acid oxidation, and digestion with proteolytic enzymes in order to monitor changes in the geometry of the protein by changes in the electron paramagnetic resonance (EPR) spectrum of the nitroxide spin-label probe. The results of these experiments indicate that the spin-label attached to histidine-105 of RNase A is sensitive to modifications affecting the conformational integrity of the molecule and to the reconstituting effects of various active-center ligands.
3-SLHis-105-核糖核酸酶A是在组氨酸-105咪唑环的3位自旋标记的核糖核酸酶A（RNase A）的一种活性衍生物。为了通过氮氧化物自旋标记探针的电子顺磁共振（EPR）光谱变化来监测蛋白质几何结构的变化，已对自旋标记的酶进行了尿素变性、还原、还原-羧甲基化、过甲酸氧化以及用蛋白水解酶消化等处理。这些实验结果表明，连接到RNase A的组氨酸-105上的自旋标记对影响分子构象完整性的修饰以及各种活性中心配体的重构作用敏感。
