Very low density lipoproteins (VLDL), S(f)60 to 400, from normolipemic individuals do not suppress 3-hydroxy-3-methylglutaryl-CoA reductase activity in cultured normal human fibroblasts at concentrations 20-fold higher than those of low density lipoproteins (LDL) that give total suppression. To determine if these VLDL contain all of the structural elements necessary for receptor-mediated suppression, they were converted in vitro with bovine milk lipoprotein lipase to low density lipoproteins. These LDL-like lipoproteins were as effective in suppression as LDL isolated directly from plasma, with half-maximal and complete suppression at 1 and 4 μg of cholesterol ml-1. Neither native LDL nor LDL produced in vitro suppressed receptor-negative fibroblasts. It is concluded that action of lipoprotein lipase on VLDL leads to a rearrangement of lipoprotein components that permits interaction of LDL produced in vitro with the LDL-specific cell surface receptor of fibroblasts and subsequent suppression of 3-hydroxy-3-methylglutaryl-CoA reductase.
|Original language||English (US)|
|Number of pages||3|
|Journal||Journal of Biological Chemistry|
|State||Published - 1979|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology