Changes in GDP binding to brown adipose tissue mitochondria and the uncoupling protein.
Incubation in vitro of brown adipose tissue (BAT) mitochondria with divalent cations, spermine, or alkaline phosphatase led to a marked increase in the binding of [3H]GDP. The effect of Mg2+ appeared to be the most specific and led to the largest increase in GDP binding. A simplified method was developed for measuring GDP binding to purified uncoupling protein from rat BAT mitochondria. Application of this method indicates that uncoupling protein from cold-acclimated rats binds twice as much GDP as uncoupling protein from cold-acclimated rats that were briefly returned to thermoneutrality, paralleling changes in GDP binding to the mitochondria. Incubation of BAT mitochondria with Mg2+ led to a smaller increase in GDP binding to the subsequently purified uncoupling protein, suggesting that divalent cations may somehow participate in the regulation of the activity of the uncoupling protein.
Swick
A G
AG
Department of Nutritional Sciences, University of Wisconsin-Madison 53706.
Swick
R W
RW
D000064:Acclimatization; D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000469:Alkaline Phosphatase; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002352:Carrier Proteins; D003080:Cold Temperature; D006150:Guanine Nucleotides / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism*; D007473:Ion Channels; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D024101:Mitochondrial Proteins; D051381:Rats; D011919:Rats, Inbred Strains; D013096:Spermine / Q000494:pharmacology; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D006150:Guanine Nucleotides; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D000071256:Uncoupling Protein 1; D006153:Guanosine Diphosphate; D013096:Spermine; D000469:Alkaline Phosphatase; D008274:Magnesium; D002118:Calcium