Nonhistone protein purified from porcine kidney acts as a suicide substrate inhibitor on furin-like enzyme  

猪肾中纯化的非组蛋白是furin样酶的自杀性底物抑制剂(英文)

作　　者：费浩[1] 李彦[1] 王丽秀 罗明娟[1] 凌敏华[1] 戚正武[1] 

机构地区：[1]中国科学院上海生物化学研究所分子生物学国家重点实验室

出　　处：《Acta Pharmacologica Sinica》2000年第3期75-80,共6页中国药理学报（英文版）

基　　金：Project supported by the State Biological High Technology Re-march Grant of China.

摘　　要：AIM: To search and purify a naturally occurring protein inhibitor of the furin-like enzyme from the porcine kidney. METHODS: Recombinant kexin, a furin-like enzyme, from the yeast secretion expression was used as a target enzyme. The inhibitor component was extracted and purified from the acetone powder of porcine kidney. The inhibitory activity was monitored using a fluorogenic peptide substrate Boc-Arg-Val-Arg-Arg-MCA at spec-trofluorimeter. RESULTS: The purified inhibitor component is a basic protein with an isoelectric point over 9.5. Its partial N-terminal sequence of 22 residues was determined, showing a high homology with nonhistone chromosomal protein HMG-17 in which there are four sites composed of dibasic residues, susceptible to be cleaved by the furin-like enzyme. This nonhistone protein could strongly compete with the fluorogenic substrate. However, this nonhistone protein would be degraded as a substrate by kexin if it was incubated with the enzyme for long time before adding the fluorogenic substrate, and subsequently lost its temporary inhibitory activity. CONCLUSION: The nonhistone protein isolated from the porcine kidney functioned as a suicide substrate inhibitor for the furin-like enzyme. proprotein convertase; furin; non-his-tone chromosomal proteins; enzyme inhibitors目的:从猪肾脏中寻找并纯化furin样酶的天然抑制剂。方法:通过酵母分泌表达系统获得furin样酶的重组Kexin。从猪肾丙酮粉中抽提并纯化抑制剂组分。抑制剂活力在荧光分光光度计上,用荧光底物Boc-Arg-Val-Arg-Arg-MCA测定。结果:纯化到的抑制剂组分是一等电点超过9.5的碱性蛋白。测定了其N末端22个残基的序列。该序列与非组蛋白HMG-17高度同源,后者含有4个易被furin样酶裂解的双碱性氨基酸位点。因此,该非组蛋白可与荧光底物强烈竞争。若将酶与非组蛋白长时间温育,其抑制剂活力将最终丧失。结论:猪肾中纯化的非组蛋白是furin样酶的自杀性底物抑制剂。

关 键 词：proprotein convertase furin non-his-tone chromosomal proteins enzyme inhibitors 

分 类 号：R914[医药卫生—药物化学]