Isolation and characterization of 3-hydroxyacyl coenzyme A dehydrogenase-binding protein from pig heart inner mitochondrial membrane.
3-Hydroxyacyl coenzyme A (CoA) dehydrogenase-binding protein was solubilized from inner mitochondrial membrane by using taurodeoxycholate at high ionic strength. The binding protein was isolated from the suspension using 3-hydroxyacyl-CoA dehydrogenase affinity chromatography. The protein eluted from the affinity column had a molecular weight of approximately 150,000, as determined by gel filtration. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the protein is a dimer consisting of 69,000 and 71,000 molecular weight subunits. The enzyme binding capacity of this protein was tested with a polyethylene glycol precipitation method: 0.5 mg of enzyme could be precipitated together with 1 mg of binding protein, showing that 1 mol of binding protein binds 1 mol of enzyme. This protein had no affinity toward malic dehydrogenase, citrate synthase, and fumarase. The approximately 2-fold increase in the 3-hydroxyacyl-CoA dehydrogenase activity when it was measured in the presence of the binding protein is additional evidence of enzyme-binding protein interaction. When incorporated into liposomes, the binding protein retained its ability to bind 3-hydroxyacyl-CoA dehydrogenase, but did not bind malic dehydrogenase, citrate synthase, and fumarase. These results suggest that the protein isolated by us has a specific function in anchoring a beta-oxidation enzyme to the matrix surface of the mitochondrial membrane.
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification*; D007425:Intracellular Membranes / Q000032:analysis*; D007700:Kinetics; D008929:Mitochondria, Heart / Q000648:ultrastructure*; D008970:Molecular Weight; D009994:Osmolar Concentration; D013552:Swine; D013657:Taurodeoxycholic Acid / Q000494:pharmacology
D002352:Carrier Proteins; D013657:Taurodeoxycholic Acid; D015094:3-Hydroxyacyl CoA Dehydrogenases