牛多形核白细胞糖原合酶I的纯化及性质

Purification and properties of glycogen synthase I from bovine polymorphonuclear leucocytes.

作者信息

Rasmussen L H, Pedersen K M, Juhl H

出版信息

Biochimie. 1985 Jun;67(6):615-23. doi: 10.1016/s0300-9084(85)80201-7.

Abstract

Glycogen synthase I was purified from bovine polymorphonuclear leucocytes (PMNs) by a procedure involving concanavalin A-Sepharose affinity chromatography. The purified glycogen-bound glycogen synthase I had a specific activity of 9.83 U/mg protein and the glycogen free enzyme 21 U/mg protein. Molecular ratio of the native enzyme and the subunit were 340 K and 85 K respectively. After phosphorylation by the catalytic subunit of cAMP-dependent protein kinase the phosphorylated sites were studied using high-performance liquid chromatography (HPLC) of the tryptic 32P-peptides. The enzyme was phosphorylated at three different sites with retention times identical to site 1a, site 1b, and site 2 from rabbit skeletal muscle glycogen synthase.

摘要

通过涉及伴刀豆球蛋白A-琼脂糖亲和层析的方法，从牛多形核白细胞（PMNs）中纯化糖原合酶I。纯化的与糖原结合的糖原合酶I的比活性为9.83 U/mg蛋白质，而游离糖原的酶为21 U/mg蛋白质。天然酶和亚基的分子比分别为340 K和85 K。经cAMP依赖性蛋白激酶催化亚基磷酸化后，使用胰蛋白酶32P-肽的高效液相色谱（HPLC）研究磷酸化位点。该酶在三个不同位点被磷酸化，其保留时间与兔骨骼肌糖原合酶的位点1a、位点1b和位点2相同。