Fatty acid binding site of the mitochondrial uncoupling protein. Demonstration of its existence by EPR spectroscopy of 5-DOXYL-stearic acid

FEBS Lett. 1994 Apr 18;343(1):22-6. doi: 10.1016/0014-5793(94)80599-7.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue, Brown / metabolism
  • Animals
  • Binding Sites
  • Biological Transport
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Cricetinae
  • Cyclic N-Oxides / analysis*
  • Electron Spin Resonance Spectroscopy
  • Fatty Acids / metabolism*
  • Hydrogen / metabolism
  • Ion Channels
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Mesocricetus
  • Mitochondria / metabolism*
  • Mitochondrial Proteins
  • Proteolipids / metabolism
  • Spin Labels
  • Uncoupling Protein 1

Substances

  • Carrier Proteins
  • Cyclic N-Oxides
  • Fatty Acids
  • Ion Channels
  • Membrane Proteins
  • Mitochondrial Proteins
  • Proteolipids
  • Spin Labels
  • Uncoupling Protein 1
  • proteoliposomes
  • 5-doxylstearic acid
  • 16-nitroxystearic acid
  • Hydrogen