Acetyl-CoA hydrolase activity and function in Ascaris suum muscle mitochondria.

Acyl-CoA compounds are stable in adult Ascaris suum mitochondrial preparations. However, when incubated in the presence of 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB), acetyl-CoA or propionyl-CoA are hydrolyzed to form free coenzyme A. This acetyl-CoA hydrolase activity has been partially purified and found to be specific for the above CoA derivatives. Gel filtration indicates an apparent molecular weight of 232,000. The hydrolase activity has been purified free from acyl-CoA transferase activities and appears not to be accounted for on the basis of a thiolase. Because Ascaris is an intestinal parasite that metabolizes primarily anaerobically and accumulates a large number of volatile fatty acids that are formed as the coenzyme A derivatives, the hydrolase would be expected to function in the regeneration of free CoA. However, how the hydrolase reaction would be pulled in the absence of the nonphysiologic DTNB is not known.