title: Fatty acid binding site of the mitochondrial uncoupling protein. Demonstration of its existence by EPR spectroscopy of 5-DOXYL-stearic acid.
abstract: Fatty acid binding site on isolated mitochondrial uncoupling protein (UcP) is demonstrated using EPR spectroscopy of 5-DOXYL-stearic acid (5-SASL), which also activated H+ transport in proteoliposomes containing UcP. In the presence of UcP the EPR spectrum showed reproducible broadening of the low field peak as well as an increase in h+1I/h+1M ratio, rotational correlation time and in order parameter. The half-height width of the low field peak was even doubled in the presence of another UcP ligand, GDP. Palmitic acid reversed the effect of 5-SASL and non-ionizable 5-DOXYL-decane did not exhibit it.
authors.affiliation: Department of Membrane Transport Biophysics, Academy of Sciences of the Czech Republic, Prague.
authors.forename: P
authors.initials: P
authors.lastname: Jezek
authors.forename: H J
authors.initials: HJ
authors.lastname: Freisleben
mesh_terms: D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D006224:Cricetinae; D003497:Cyclic N-Oxides / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D005227:Fatty Acids / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D007473:Ion Channels; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008647:Mesocricetus; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D011510:Proteolipids / Q000378:metabolism; D013113:Spin Labels; D000071256:Uncoupling Protein 1
chemical_list: D002352:Carrier Proteins; D003497:Cyclic N-Oxides; D005227:Fatty Acids; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011510:Proteolipids; D013113:Spin Labels; D000071256:Uncoupling Protein 1; C020485:proteoliposomes; C005072:5-doxylstearic acid; C032363:16-nitroxystearic acid; D006859:Hydrogen