Abduragimov A R, Itkes A V, Kochetkov S N, Tunitskaia V L, Tiurkin V V
Biokhimiia. 1987 Nov;52(11):1798-807.
A heat-stable protein inhibitor of cAMP-dependent protein kinase has been isolated from pig brain tissue. During gel filtration the protein is eluted in three peaks corresponding to the tetramer, dimer and monomer. The monomer fraction was purified 609-fold. The molecular mass of the monomeric form as determined by gel filtration and electrophoresis is equal to 11,000 Da and 8000 Da, respectively. The inhibition of the phosphotransferase reaction with respect to ATP occurs via a non-competitive mechanism, while that for histone--via a competitive mechanism. A formal kinetic analysis of various modes of the inhibitor binding to different protein kinase forms, e. g., the cAMP-dependent protein kinase catalytic subunit, protein kinase holoenzyme in the presence and absence of cAMP as well as of holoenzyme preparations modified by dimethylsuberimidate and cupric 1,10-phenanthroline, has been carried out. It was demonstrated that 3-4 inhibitor molecules are involved in the interaction with protein kinase.
一种对环磷酸腺苷（cAMP）依赖性蛋白激酶具有热稳定性的蛋白抑制剂已从猪脑组织中分离出来。在凝胶过滤过程中，该蛋白以三个峰被洗脱出来，分别对应四聚体、二聚体和单体。单体部分被纯化了609倍。通过凝胶过滤和电泳测定，单体形式的分子量分别为11,000道尔顿和8000道尔顿。相对于ATP的磷酸转移酶反应的抑制通过非竞争性机制发生，而对组蛋白的抑制则通过竞争性机制。对抑制剂与不同蛋白激酶形式（例如cAMP依赖性蛋白激酶催化亚基、存在和不存在cAMP时的蛋白激酶全酶以及经二甲基辛二亚胺和1,10 - 菲咯啉铜修饰的全酶制剂）结合的各种模式进行了形式动力学分析。结果表明，3 - 4个抑制剂分子参与与蛋白激酶的相互作用。
