Abstract
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) |
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Pages (from-to) | 1007-1009 |
Number of pages | 3 |
Journal | Journal of Biological Chemistry |
Volume | 254 |
Issue number | 4 |
State | Published - 1979 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology