Chapter 11 Lipoprotein lipase
1987; Elsevier BV; Linguagem: Inglês
10.1016/s0167-7306(08)60205-7
ISSN1875-7901
AutoresArlene S. Garfinkel, Michael C. Schotz,
Tópico(s)Diabetes, Cardiovascular Risks, and Lipoproteins
ResumoThis chapter highlights lipoprotein lipase (LPL), an enzyme of the lipid transport system. The primary function of LPL in the lipid transport system is catalysis of the core triglyceride of circulating chylomicrons and very low-density lipoproteins (VLDL). LPL is synthesized in parenchymal cells, secreted, and bound to endothelial cell. The enzyme, thus, has its site of physiological action at capillary endothelial surfaces where circulating lipoprotein particles are bound and the triglyceride is hydrolyzed. LPL is necessary for the initial lipolysis of triglyceride to diglyceride, and apparently also for hydrolysis of diglyceride to monoglyceride. Three characteristics that distinguish LPL from other lipases include (1) LPL is characterized by an alkaline pH optimum, (2) inhibition by low concentrations of NaCl, and (3) the requirement for apolipoprotein C-II for maximal activity. The requirement for apolipoprotein C-II for optimal LPL activity is a well-established property of the enzyme. Apolipoprotein C-II is a 78 amino acid polypeptide present on chylomicrons, VLDL, and high-density lipoproteins (HDL). The portion of the C-II molecule that specifically activates LPL and another domain responsible for lipid binding have been determined with the use of chemically modified and synthetic apoprotein C-II fragments.
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