期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1977
卷号:74
期号:12
页码:5358-5362
DOI:10.1073/pnas.74.12.5358
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Apolipoprotein C-II (apoC-II) is a small protein found associated with the plasma lipoproteins. It serves a unique function in the activation of the enzyme lipoprotein lipase (triacylglycerol acyl-hydrolase, EC 3.1.1.3 ). ApoC-II contains a single arginine residue, permitting tryptic cleavage into two peptides after succinylation of the native protein. The succinylated amino-terminal peptide, approximately 50 residues, did not activate lipoprotein lipase. The succinylated carboxyl-terminal peptide, about 29 residues, had significant cofactor activity. Relative to native apoC-II, the maximal activation observed with the succinylated carboxyl-terminal peptide was 50% lower and the concentration required for half-maximal activity was approximately 10 times higher. Mixtures of the carboxyl- and amino-terminal peptides had no more activity than the carboxyl-terminal peptide alone. Localization of functional properties to the carboxyl region is a feature also common to apolipoproteins C-III, A-II, and A-I.