Williamson J, Greene J, Chérif S, Milner-White E J
Biochem J. 1977 Dec 1;167(3):731-7. doi: 10.1042/bj1670731.
By using sodium dodecyl sulphage/polyacrylamide-gel electrophoresis it was shown that rabbit muscle creatine kinase, both in a homogenate and purified, appears to be composed of a mixture of two peptides (mol.wts. 42100 and 40300) differing in length by about 15 amino acids. It is found that low concentrations of proteinase K from the fungus Tritirachium album can cleave about 38 amino acids from each chain of creatine kinase, leaving two large fragments (mol.wts 37700 and 35500). Scission of the whole enzyme was found to be concomitant with complete loss of enzyme activity. MgADP in the presence of absence of creatine slowed the rate of proteolysis by about 50%, but the transition-state analogue complex creatine-NO3--MgADP appeared to protect completely. The time course for the proteolytic inactivation in the presence of this complex, but not in its absence, was biphasic.
通过使用十二烷基硫酸钠/聚丙烯酰胺凝胶电泳表明，兔肌肉肌酸激酶无论是在匀浆中还是纯化后，似乎都由两种长度相差约15个氨基酸的肽（分子量分别为42100和40300）组成。发现来自米曲霉的低浓度蛋白酶K可从肌酸激酶的每条链上切割约38个氨基酸，留下两个大片段（分子量分别为37700和35500）。发现整个酶的裂解与酶活性的完全丧失同时发生。在有或没有肌酸存在的情况下，MgADP可使蛋白水解速率减慢约50%，但过渡态类似物复合物肌酸-NO3--MgADP似乎具有完全的保护作用。在有这种复合物存在而非不存在的情况下，蛋白水解失活的时间进程是双相的。
