Inagaki F, Watanabe K, Miyazawa T
J Biochem. 1979 Aug;86(2):591-4. doi: 10.1093/oxfordjournals.jbchem.a132561.
The 270 MHZ proton MNR spectra of an aqueous solution of ribonuclease A in the presence of hexacyanochromate ions were measured. The C2 and C4 proton signals of the His 12 and His 119 residues were selectively broadened, indicating that this ion was bound to the active site. From analyses of concentration dependences of diamagnetic shifts, one hexacyanocobaltate ion was found to bind to the active site, with the dissociation constant of 8 mM. The paramagnetic hexacyanochromate ion is useful for mapping the active sites of enzymes for anionic substrates.
在六氰基铬酸根离子存在的情况下，测量了核糖核酸酶A水溶液的270兆赫质子核磁共振谱。组氨酸12和组氨酸119残基的C2和C4质子信号被选择性加宽，表明该离子与活性位点结合。通过对抗磁位移浓度依赖性的分析，发现一个六氰基钴酸根离子与活性位点结合，解离常数为8毫摩尔。顺磁性的六氰基铬酸根离子可用于绘制阴离子底物酶活性位点的图谱。
