ATP synthesis in the disk membranes of rod outer segments of bovine retina

J Photochem Photobiol B. 2002 Mar;66(2):148-52. doi: 10.1016/s1011-1344(02)00238-5.

Abstract

ATP is synthesized on the disk membrane isolated from rod outer segments of the bovine retina. Together with a slow component which accounted for a constant rate of about 22 nmol ATP/min/mg of protein and which was due to the adenylate kinase activity, a fast component with a maximal activity of about 58 nmol ATP/min/mg of protein was measured at physiological calcium concentrations. This fast activity disappeared in the presence of the Ca(2+) ionophore A23187, was inhibited by vanadate or thapsigargin but not by oligomycin, suggesting that this ATP synthesis is due to the reversal functioning of the Ca(2+)-ATPase previously found on the disk membranes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / pharmacology
  • Adenosine Triphosphate / biosynthesis*
  • Animals
  • Calcimycin / pharmacology
  • Calcium / metabolism
  • Calcium-Transporting ATPases / metabolism*
  • Cattle
  • Enzyme Inhibitors / pharmacology
  • Ionophores / pharmacology
  • Rod Cell Outer Segment / drug effects
  • Rod Cell Outer Segment / enzymology*
  • Thapsigargin / pharmacology

Substances

  • Enzyme Inhibitors
  • Ionophores
  • Calcimycin
  • Adenosine Diphosphate
  • Thapsigargin
  • Adenosine Triphosphate
  • Calcium-Transporting ATPases
  • Calcium