|Title||Uptake of oleate by isolated rat adipocytes is mediated by a 40-kDa plasma membrane fatty acid binding protein closely related to that in liver and gut.|
|Publication Type||Journal Article|
|Year of Publication||1988|
|Authors||Schwieterman W, Sorrentino D, Potter BJ, Rand J, Kiang CL, Stump D, Berk PD|
|Journal||Proc Natl Acad Sci U S A|
|Date Published||1988 Jan|
|Keywords||Adipose Tissue, Animals, Carrier Proteins, Cell Membrane, Fatty Acid-Binding Protein 7, Fatty Acid-Binding Proteins, Fluorescent Antibody Technique, In Vitro Techniques, Intestinal Mucosa, Kinetics, Liver, Male, Molecular Weight, Neoplasm Proteins, Nerve Tissue Proteins, Oleic Acid, Oleic Acids, Organ Specificity, Rats, Rats, Inbred Strains|
A portion of the hepatocellular uptake of nonesterified long-chain fatty acids is mediated by a specific 40-kDa plasma membrane fatty acid binding protein, which has also been isolated from the gut. To investigate whether a similar transport process exists in other tissues with high transmembrane fatty acid fluxes, initial rates (Vo) of [3H]oleate uptake into isolated rat adipocytes were studied as a function of the concentration of unbound [3H]oleate in the medium. Vo reached a maximum as the concentration of unbound oleate was increased (Km = 0.30 +/- 0.03 microM; Vmax = 2470 +/- 90 pmol/min per 5 X 10(4) adipocytes) and was significantly inhibited both by phloretin and by prior incubation of the cells with Pronase. A rabbit antibody to the rat liver plasma membrane fatty acid binding protein inhibited adipocyte fatty acid uptake by up to 63% in dose-dependent fashion. Inhibition was noncompetitive; at an immunoglobulin concentration of 250 micrograms/ml Vmax was reduced from 2480 +/- 160 to 1870 +/- 80 pmol/min per 5 X 10(4) adipocytes, with no change in Km. A basic (pI approximately equal to 9.1) 40-kDa adipocyte plasma membrane fatty acid binding protein, isolated from crude adipocyte plasma membrane fractions, reacted strongly in both agar gel diffusion and electrophoretic blots with the antibody raised against the corresponding hepatic plasma membrane protein. These data indicate that the uptake of oleate by rat adipocytes is mediated by a 40-kDa plasma membrane fatty acid binding protein closely related to that in liver and gut.
|Alternate Journal||Proc Natl Acad Sci U S A|
|PubMed Central ID||PMC279547|
|Grant List||AA-06860 / AA / NIAAA NIH HHS / United States |
AM-26438 / AM / NIADDK NIH HHS / United States
Jacob H. Rand, M.D.