The activating effect of fatty acid on the mitochondrial uncoupling protein reconstituted in liposomes.
The valinomycin-induced H+ uptake in liposomes with reconstituted uncoupling protein from brown adipose tissue mitochondria is greatly enhanced when palmitic acid (4-20 micrograms/mg lipid) is incorporated prior to proteoliposome preparation. This procedure does not change basal H+ permeability of the liposomes. H+ uptake in proteoliposomes is inhibited by GDP, the net GDP-sensitive H+ flux being higher when palmitic acid was incorporated than in its absence. The net palmitate-induced increment of H+ uptake decreases with increasing concentration of GDP. These results suggest that palmitate augments H+ flux via the uncoupling protein and that direct interaction of palmitate with the uncoupling protein occurs during such activation within the hydrophobic core of the membrane.
Jezek
P
P
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Drahota
Z
Z
Ring
K
K
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001693:Biological Transport, Active / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism*; D066298:In Vitro Techniques; D007473:Ion Channels; D008081:Liposomes; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism / Q000494:pharmacology*; D010539:Permeability; D011522:Protons; D051381:Rats; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D007473:Ion Channels; D008081:Liposomes; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D010169:Palmitic Acids; D011522:Protons; D000071256:Uncoupling Protein 1; D019308:Palmitic Acid