一种牛初乳源生长因子的纯化与特性分析

Purification and characterization of a bovine colostrum-derived growth factor.

作者信息

Shing Y, Klagsbrun M

机构信息

Department of Biological Chemistry, Children's Hospital, Boston, Massachusetts 02115.

出版信息

Mol Endocrinol. 1987 May;1(5):335-8. doi: 10.1210/mend-1-5-335.

DOI:10.1210/mend-1-5-335

PMID:3274892

Abstract

A growth factor in bovine colostrum was purified to homogeneity by a combination of acid extraction, boiling, cation exchange chromatography, isoelectric focusing, and reverse phase HPLC. The bovine colostrum growth factor (BCGF) had an isoelectric point of about 10, a native mol wt of about 30,000, was resistant to inactivation by boiling and exposure to pH 1, but was inactivated by dithiothreitol. BCGF appeared to be structurally related to human platelet-derived growth factor (PDGF) and competed with human PDGF in a radioreceptor assay. However, while human PDGF appeared to be a heterodimer of 17,000 and 14,000 mol wt subunits, BCGF appeared to be a homodimer of 20,000 mol wt subunits. Purified BCGF had a specific activity in stimulating 3T3 cell proliferation of about 3-6 U/ng and was active at about 1-2 ng/ml.

摘要

通过酸提取、煮沸、阳离子交换色谱、等电聚焦和反相高效液相色谱相结合的方法，将牛初乳中的一种生长因子纯化至同质。牛初乳生长因子（BCGF）的等电点约为10，天然分子量约为30,000，对煮沸和暴露于pH 1具有抗性，但会被二硫苏糖醇灭活。BCGF在结构上似乎与人类血小板衍生生长因子（PDGF）相关，并且在放射受体测定中与人PDGF竞争。然而，虽然人PDGF似乎是由17,000和14,000分子量亚基组成的异二聚体，但BCGF似乎是由20,000分子量亚基组成的同二聚体。纯化的BCGF在刺激3T3细胞增殖方面的比活性约为3 - 6 U/ng，在约1 - 2 ng/ml时具有活性。