Activation of lipoprotein lipase by apolipoprotein CII

Functional analyses of human apolipoprotein CII by site-directed mutagenesis: identification of residues important for activation of lipoprotein lipase.

Apolipoprotein CII (apoCII) activates lipoprotein lipase (LPL). Seven residues, located on one face of a model alpha-helix spanning residues 59-75, are fully conserved in apoCII from ten different animal species. We have mutated these residues one by one. Substitution of Ala(59) by glycine, or Thr(62) and Gly(65) by alanine did not change the activation, indicating that these residues are outsi...

bis-ANS acts as an inhibitor of lipoprotein lipase and competes for binding with apolipoprotein CII

Activation of Lipoprotein Lipase

Lipoprotein lipase (LPL) from rat heart acetone powders has been reported to depend on the presence of NH4 + , calcium, or other divalent cations for optimal activity. In addition, the enzyme will not hydrolyze an artificial triglyceride emulsion unless it is converted to an active substrate by the addition of very low density lipoproteins, high density lipoproteins (HDL), or certain peptides c...

Activation of lipoprotein lipase by lipoprotein fractions of human serum.

Triglycerides in fat emulsions are hydrolyzed by lipoprotein lipase only when they are "activated" by serum lipoproteins. The contribution of different lipoprotein fractions to hydrolysis of triglycerides in soybean oil emulsion was assessed by determining the quantity of lipoprotein fraction required to give half-maximal hydrolysis. Most of the activator property of whole serum from normolipid...

Impaired lipoprotein lipase activation by uraemic and post-transplant sera.

1. Lipoprotein lipase was separated from normal human post-heparin plasma by affinity chromatography and assayed with a 14C-labelled triolein emulsion. No enzyme activity was detected unless whole serum was included in the assay as a source of cofactor, apolipoprotein C-II. 2. After a 10 h fast, serum obtained from 46 normal subjects, eight patients with hypertriglyceridaemia but normal renal f...