一种抑制蛋白激酶CK_2活性的新多肽的分离和鉴别

Isolation and Identification of a New Peptide that Inhibits Protein Kinase CK_2

从猪肾上腺髓质嗜铬细胞分泌颗粒裂解物中纯化出 3种新多肽 ,经N 末端降解分析和质谱测定 ,它们分别位于猪嗜铬颗粒蛋白A(CgA) 3 0 8— 3 2 4、3 0 8— 3 2 8及 3 0 8— 3 2 9肽段 ,具有相同N 端区 ,而C 端长度不同。合成的CgA 3 0 8— 3 2 4肽段 ,即GN 1 7在浓度低于 6μmol/L时即可竞争性抑制CK2 活性 ,IC50 为 5 0 μmol/L。

Three new peptides were purified from porcine chromaffin granule lysate, sequenced by N-terminal degradation and identified with mass spectrometry. They were located at chromogranin A 308—324, 308—328 and 308—329; sharing the same N-terninus but with diffferent extends at the C-terninus. The short form of the peptide (CgA 308—324, GN-17) was synthesized and was found to competitively inhibit CK 2 activity at a concentrition as low as 6 μmol/L. The half-maximal inhibition reached at peptide concentration of about 50 μmol/L.