Rapid hepatic clearance of the canine lipoproteins containing only the E apoprotein by a high affinity receptor. Identity with the chylomicron remnant transport process
| Autor: | Robert W. Mahley, B C Sherrill, Thomas L. Innerarity |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
medicine.medical_specialty
Familial dysbetalipoproteinemia digestive oral and skin physiology Hepatic clearance Cell Biology Biology medicine.disease Biochemistry Endocrinology Chylomicron remnant Internal medicine Rat liver medicine lipids (amino acids peptides and proteins) Enzyme kinetics Binding site Receptor Molecular Biology Perfusion |
| Zdroj: | Journal of Biological Chemistry. 255:1804-1807 |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/s0021-9258(19)85951-3 |
| Popis: | The canine lipoproteins containing only the E apoprotein (apo-E HDLc), when perfused through a rat liver, display high affinity, receptor-mediated uptake, and saturation kinetics. These data indicate that the hepatic uptake of apo-E HDLc proceeds via a finite number of binding sites. The kinetic values determined for apo-E HDLc binding and uptake during a single-pass perfusion through a rate liver are: Km = 4.99 micrograms of protein . ml-1 and Vmax = 6.42 microgram of protein . g-1 . min-1. On a molar basis, the hepatic extraction of apo-E HDLc is almost equivalent to the high hepatic extraction of a class of lipoproteins that is most avidly removed from systemic circulation--the rat chylomicron remnants. Competition experiments between apo-E HDLc and rat chylomicron remnants indicate that the hepatic uptake mechanism for the two macromolecules is identical. Given that the recognition of apo-E HDLc is mediated by the E apoprotein and that the kinetic uptake properties of chylomicron remnants and apo-E HDLc are almost identical, it is probable that the E apoprotein is the major determinant responsible for hepatic chylomicron remnant recognition. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|