人胎盘脯氨酸后内切酶的纯化及性质

Purification and properties of a human placental post-proline endopeptidase.

作者信息

Sumi S, Mizutani S, Narita O, Tomoda Y

出版信息

Nihon Sanka Fujinka Gakkai Zasshi. 1984 Oct;36(10):1943-51.

Abstract

Post-proline endopeptidase (EC 3.4.21.26) was found in human placenta, purified 3,390-fold and characterized. The post-proline endopeptidase was able to be completely separated from dipeptidyl peptidase IV (EC 3.4.14.5) by hydrophobic phenyl Sepharose chromatography. The pH optimum of the enzyme was 6.7. The Km value for 7-(succinyl-Gly-Pro)-4-methylcumarineamide was 1.0mM. The molecular weight of this enzyme was estimated to be 140,000 by gel filtration and 67,000 by sodium dodecyl sulfate gel electrophoresis, indicating its dimetric structure. Human placental post-proline endopeptidase appeared to be a thiol protease in view of the results of inhibition studies.

摘要

脯氨酸后内切酶（EC 3.4.21.26）在人胎盘中被发现，经过3390倍纯化并进行了特性鉴定。通过疏水苯基琼脂糖凝胶层析，脯氨酸后内切酶能够与二肽基肽酶IV（EC 3.4.14.5）完全分离。该酶的最适pH值为6.7。7-（琥珀酰-甘氨酰-脯氨酸）-4-甲基香豆素酰胺的Km值为1.0mM。通过凝胶过滤法估计该酶的分子量为140,000，通过十二烷基硫酸钠凝胶电泳法估计为67,000，表明其为二聚体结构。从抑制研究结果来看，人胎盘脯氨酸后内切酶似乎是一种巯基蛋白酶。