Human Lipoprotein Lipase: Important Roles Of A Specific N-Linked Glycosylation Site And Specific Serines In Secretion And Enzyme Activity

Abstract

Thestructure-function relationship of human lipoprotein lipase was studied by expressionof the cloned cDNAin transfected cells, using the wildtype construct and site-specific mutant constructs. Asparagine 43, of one ofthe two potential N-linked glycosylationsites in lipoprotein lipase, was found to be important for both enzymeactivity and secretion. Mutations involving someoftheserine residues also produced marked changes in enzymeactivity. The possible structural changes associated with these functionally altered mutantlipoprotein lipase molecules are discussed with reference to the crystal structure of human pancreatic lipase, a lipolytic enzyme with considerable sequence homology to lipoprotein lipase.