Esterase-type of activity possessed by human plasma apolipoprotein C-II and its synthetic fragments. Academic Article uri icon

Overview

abstract

  • Human plasma apolipoproteins apo A-I, A-II, C-I, C-II and C-III (with the exception of apoE), porcine pancreatic colipase and procolipase hydrolyze 4-methylumbelliferyloleate. In all cases, liberation of 4-methylumbelliferone could be inhibited by phenylmethylsulfonyl-fluoride, thus suggesting the involvement of serine residues. To the best of our knowledge this is the first report on the esterase activities of these peptides. Synthetic fragments of the lipoprotein lipase activator, apoC-II, prepared according to the known sequence, also possessed this esterase-type of activity. Furthermore, the esterase-type of activities of the synthetic apoC-II fragments with different chain lengths bore a relatively good correlation to the reported abilities of these peptides to produce activation of lipoprotein lipase. We propose a model for the mechanism of activation of lipoprotein lipase by apolipoprotein C-II. ApoC-II would enhance the apparent catalytic rate constant of lipoprotein lipase by functioning as a specific acyl-enzyme hydrolase. A similar catalytic mechanism is suggested for other protein co-factors of hydrolytic enzymes.

publication date

  • July 1, 1983

Research

keywords

  • Apolipoproteins
  • Apolipoproteins C
  • Esterases

Identity

Scopus Document Identifier

  • 0020788976

Digital Object Identifier (DOI)

  • 10.1016/0009-3084(83)90004-x

PubMed ID

  • 6627523

Additional Document Info

volume

  • 33

issue

  • 1