A direct pathway for the metabolism of propionate in cell extracts from Moraxella lwoffi.
1. Extracts from Moraxella lwoffi oxidize propionate, but at a low rate when compared with whole cells. 2. This oxidative activity requires the formation of propionyl-CoA. 3. Enzymes catalysing the formation of propionyl phosphate and propionyl-CoA are present. The presence of a propionyl-CoA hydrolase is considered to be an artifact, but partly responsible for the low rates of oxidation. 4. Enzymes catalysing the reduction of NAD(+) and the formation of pyruvate with propionyl-CoA as substrate are also present. 5. That the only pathway for the metabolism of propionate in extracts is a direct one to acetate via pyruvate was confirmed by the use of (14)C-labelled materials. 6. A possible sequence of enzyme-catalysed reactions that will account for the experimental observations is described.
D000085:Acetates / Q000378:metabolism; D000217:Acyltransferases / Q000378:metabolism; D002247:Carbon Isotopes; D002474:Cell-Free System; D003065:Coenzyme A / Q000378:metabolism; D004950:Esterases / Q000378:metabolism; D007651:Keto Acids / Q000378:metabolism; D008954:Models, Biological; D009016:Moraxella / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D010770:Phosphotransferases / Q000378:metabolism; D011422:Propionates / Q000378:metabolism*; D011773:Pyruvates / Q000378:metabolism
D000085:Acetates; D002247:Carbon Isotopes; D007651:Keto Acids; D011422:Propionates; D011773:Pyruvates; D000217:Acyltransferases; D010770:Phosphotransferases; D004950:Esterases; D003065:Coenzyme A