title: Hydrolysis of long-chain fatty acyl-CoA in homogenates of human blood platelets: the existence of a platelet palmitoyl-CoA hydrolase.
abstract: The existence of a very active long-chain fatty acyl-CoA hydrolase in homogenates of human blood platelets is reported. The highest activity was found with palmitoyl-CoA as the substrate. Palmitoyl-CoA hydrolase activity was not found in intact platelets indicating that the enzyme is localized within the platelet membrane. No palmitoyl-CoA hydrolase activity was found in fasting plasma. Mg2+, Mn2+, Ca2+ and Triton X-100 inhibited the palmitoyl-CoA hydrolase activity. Sulphydryl reagents had no effect, whereas high concentrations of D- and L-carnitine inhibited the activity. Carnitine palmitoyltransferase did not interfere with the assay of palmitoyl-CoA hydrolysis as the activity of carnitine-palmitoyl hydrolase was less than 1% of the palmitoyl-CoA hydrolase activity.
mesh_terms: D000214:Acyl Coenzyme A / Q000097:blood / Q000378:metabolism*; D001792:Blood Platelets / Q000201:enzymology* / Q000378:metabolism; D001798:Blood Proteins / Q000494:pharmacology; D002331:Carnitine / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002788:Cholesterol Esters / Q000097:blood; D003065:Coenzyme A / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D007202:Indicators and Reagents; D009711:Nucleotides / Q000494:pharmacology; D010168:Palmitates / Q000494:pharmacology; D010170:Palmitoyl-CoA Hydrolase / Q000097:blood*; D010743:Phospholipids / Q000097:blood; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013696:Temperature; D013869:Thiolester Hydrolases / Q000097:blood*; D014280:Triglycerides / Q000097:blood
chemical_list: D000214:Acyl Coenzyme A; D001798:Blood Proteins; D002788:Cholesterol Esters; D007202:Indicators and Reagents; D009711:Nucleotides; D010168:Palmitates; D010743:Phospholipids; D013438:Sulfhydryl Compounds; D014280:Triglycerides; D012710:Serum Albumin, Bovine; D013869:Thiolester Hydrolases; D010170:Palmitoyl-CoA Hydrolase; D002331:Carnitine; D003065:Coenzyme A