title: 6-Methylsalicylic acid synthetase from Penicillium patulum. Some catalytic properties of the enzyme and its relation to fatty acid synthetase.
abstract: 1. The specificity of 6-methylsalicylic acid synthetase with respect to the priming substrate was studied. If acetyl-CoA was replaced by propionyl-CoA 6-ethylsalicylic acid was synthesized. The rate of this synthesis was about 13% that of 6-methylsalicylic acid synthesis in presence of acetyl-CoA. 2. 6-Methylsalicylic acid synthetase contains an acetyl transferase activity as demonstrated by the transfer of acetyl residues from acetyl-CoA to pantetheine. This transferase also catalyses propionyl transfer but only with an about 13 times slower rate. 3. Analogous to fatty acid synthetase, treatment with iodoacetamide converts 6-methylsalicylic acid synthetase into a malonyl-CoA decarboxylase. Under certain conditons the iodoacetamide-treated enzyme could catalyse 6-methylsalicylic acid formation from malonyl CoA and NADPH without the external addition of acetyl CoA.
mesh_terms: D000105:Acetyl Coenzyme A / Q000494:pharmacology; D000123:Acetyltransferases / Q000378:metabolism*; D000217:Acyltransferases; D002262:Carboxy-Lyases / Q000378:metabolism; D004790:Enzyme Induction; D064429:Fatty Acid Synthases / Q000378:metabolism*; D007460:Iodoacetamide / Q000494:pharmacology; D007700:Kinetics; D008025:Ligases / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D010088:Oxidoreductases; D010407:Penicillium / Q000201:enzymology*; D011485:Protein Binding; D012459:Salicylates / Q000494:pharmacology
chemical_list: D009097:Multienzyme Complexes; D012459:Salicylates; D000105:Acetyl Coenzyme A; D010088:Oxidoreductases; D000217:Acyltransferases; D000123:Acetyltransferases; D064429:Fatty Acid Synthases; D002262:Carboxy-Lyases; C021587:6-methylsalicylic acid synthetase; D008025:Ligases; D007460:Iodoacetamide