title: Changes in GDP binding to brown adipose tissue mitochondria and the uncoupling protein.
abstract: 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.
authors.affiliation: Department of Nutritional Sciences, University of Wisconsin-Madison 53706.
authors.forename: A G
authors.initials: AG
authors.lastname: Swick
authors.forename: R W
authors.initials: RW
authors.lastname: Swick
mesh_terms: 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
chemical_list: 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