Photoaffinity labeling of hamster brown adipose tissue mitochondria by an [125I] coenzyme A derivative: differential interaction with the uncoupling protein and ADP/ATP carrier.
We have recently synthesized an azido [125I] CoA photolabel, N-(3-iodo-4-azidophenyl propionamide) cysteinyl-5-(2'thiopyridyl cysteine) CoA that specifically labeled the ADP/ATP carrier in beef heart mitochondria. In this study brown adipose tissue mitochondria were photolabeled with the azido [125I] ACT-CoA derivative with or without inhibitors. SDS gel electrophoresis and autoradiography of the separated proteins revealed exclusive photolabeling of two polypeptides corresponding to the ADP/ATP carrier and uncoupling protein. In the presence of carboxyatracytloside only the 32 kD UCP was labeled by [125I] ACT-CoA, whereas preincubation with GDP resulted in exclusive photolabeling of the 30 kD ADP/ATP carrier. Palmitoyl CoA but not palmitic acid inhibited photolabeling of both polypeptides.
Woldegiorgis
G
G
Department of Medicine, University of Wisconsin, Madison 53706.
Duff
T
T
Contreras
L
L
Shrago
E
E
Ruoho
A E
AE
D000214:Acyl Coenzyme A / Q000031:analogs & derivatives / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000502:physiology*; D000345:Affinity Labels; D000818:Animals; D001278:Atractyloside / Q000031:analogs & derivatives / Q000494:pharmacology; D002352:Carrier Proteins; D006224:Cricetinae; D006153:Guanosine Diphosphate / Q000494:pharmacology; D007473:Ion Channels; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000502:physiology*; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D024101:Mitochondrial Proteins; D008970:Molecular Weight; D009713:Nucleotidyltransferases / Q000378:metabolism*; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D011685:Purine Nucleotides / Q000378:metabolism; D000071256:Uncoupling Protein 1
D000214:Acyl Coenzyme A; D000345:Affinity Labels; D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011685:Purine Nucleotides; D000071256:Uncoupling Protein 1; D006153:Guanosine Diphosphate; D010171:Palmitoyl Coenzyme A; D001278:Atractyloside; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases; C003853:carboxyatractyloside