Srinivasan J, Koszelak M, Mendelow M, Kwon Y G, Lawrence D S
Department of Chemistry, State University of New York, Buffalo 14226, USA.
Biochem J. 1995 Aug 1;309 ( Pt 3)(Pt 3):927-31. doi: 10.1042/bj3090927.
The substrate sequence specificity of the cdc2 protein kinase from Pisaster ochraceus has been evaluated. The peptide, Ac-Ser-Pro-Gly-Arg-Arg-Arg-Arg-Lys-amide, serves as an efficient cdc2 kinase substrate with a Km of 1.50 +/- 0.04 microM and a Vmax. of 12.00 +/- 0.18 mumol/min per mg. The amino acid sequence of this peptide is not based on any sequence in a known protein substrate of the cyclin-dependent kinase, but rather was designed from structural attributes that appear to be important in the majority of cdc2 substrates. The cyclin-dependent enzyme is remarkably indiscriminate in its ability to recognize and phosphorylate peptides that contain an assortment of structurally diverse residues at the P-2, P-1 and P+2 positions. However, peptides that contain a free N-terminal serine or lack an arginine at the P+4 position are relatively poor substrates. These aspects of the substrate specificity of the cdc2 protein kinase are compared and contrasted with the previously reported substrate specificity of a cdc2-like protein kinase from bovine brain [Beaudette, Lew and Wang (1993) J. Biol. Chem. 268, 20825-20830].
对赭色海星（Pisaster ochraceus）的cdc2蛋白激酶的底物序列特异性进行了评估。肽Ac-Ser-Pro-Gly-Arg-Arg-Arg-Arg-Lys-酰胺可作为一种有效的cdc2激酶底物，其Km为1.50±0.04 microM，Vmax为每毫克12.00±0.18微摩尔/分钟。该肽的氨基酸序列并非基于细胞周期蛋白依赖性激酶已知蛋白底物中的任何序列，而是根据在大多数cdc2底物中似乎很重要的结构特征设计的。这种细胞周期蛋白依赖性酶在识别和磷酸化在P-2、P-1和P+2位置含有各种结构不同残基的肽的能力方面非常不挑剔。然而，在P+4位置含有游离N端丝氨酸或缺乏精氨酸的肽是相对较差的底物。将cdc2蛋白激酶底物特异性的这些方面与先前报道的来自牛脑的cdc2样蛋白激酶的底物特异性进行了比较和对比[Beaudette、Lew和Wang（1993年）《生物化学杂志》268，20825 - 20830]。
