The anaerobic formation of propionic acid in the mitochondria of the lugworm Arenicola marina

摘要: The anaerobic transformation of malate and succinate into propionate was demonstrated in homogenates mitochondria isolated from the body wall musculature ofArenicola marina, a facultative polychaete. Synthesis enhanced by addition ADP. In presence malate, acetate formed to propionate. Maximal quantities both fatty acids were produced incubated with succinate, Since rate production this case about same as when related fresh weight, it is concluded that enzymatic system involved localized exclusively mitochondria. correlated concentration saturation being reached at 5 mM. tracer experiments using (methyl-14C)-malonyl-CoA, 2,3-14C-succinate, 1-14C-propionate precursors, pathway examined. results indicate methylmalonyl-CoA an intermediary product. It shown synthesis coupled formation ATP. ratio ATP/propionate 0.76. Dinitrophenol had only slight effect on ratio, although utilization inhibited considerably. vivo substrate level phosphorylation occurs equimolar succinate.