Hagiwara T, Nakaya K, Nakamura Y
School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
Biochem Int. 1990;20(5):913-9.
The nonapeptide DTDSEEEIR, corresponding to amino acid residues 78-86 of calmodulin, was synthesized, and its kinetics of phosphorylation by casein kinase 2 was examined. In the presence of 4 microM polylysine, the phosphorylation rate by casein kinase 2 was 16 times greater than that of synthetic substrate peptide RRREEETEEE reported previously, and almost 1 mol of 32p was incorporated per mol of nonapeptide in 60 min at 37 degrees C. The peptide was not phosphorylated by any other protein kinase. The Thr residue was phosphorylated by casein kinase 2, but Ser was not. The Km value of casein kinase 2 for the nonapeptide was 60 microM, comparable to that of casein, and Vmax for the nonapeptide was 4 times greater than that for casein. Addition of polylysine did not affect the Km value but markedly increased Vmax.
合成了与钙调蛋白78 - 86位氨基酸残基相对应的九肽DTDSEEEIR，并检测了其被酪蛋白激酶2磷酸化的动力学。在存在4 microM聚赖氨酸的情况下，酪蛋白激酶2的磷酸化速率比先前报道的合成底物肽RRREEETEEE高16倍，在37℃下60分钟内每摩尔九肽几乎掺入1摩尔32P。该肽不会被任何其他蛋白激酶磷酸化。苏氨酸残基被酪蛋白激酶2磷酸化，但丝氨酸未被磷酸化。酪蛋白激酶2对该九肽的Km值为60 microM，与酪蛋白相当，该九肽的Vmax比酪蛋白高4倍。添加聚赖氨酸不影响Km值，但显著增加Vmax。
