Effects of maleate on CoA metabolism in rat kidney.

CoA transfer from acetoacetyl-CoA to maleate catalyzed by purified CoA transferase was studied. The thioester product of the reaction undergoes further chemical transformations and the final product appeared to be stable CoA derivative showing neither free SH group nor hydrolyzable thio-acyl bond. Similar product was obtained as the result of the reaction of addition of CoA to the double bond of maleic anhydride. This was confirmed by DEAE-chromatography. The decrease of free CoA and acid soluble acyl-CoA in kidney mitochondria respiring in the presence of maleate or in the kidney of maleate-treated rats occured without appreciable changes in acid insoluble acyl-CoA derivatives. As the result substantial loss of total content of CoA was found. The data indicate that maleate binds and removes CoA in the form of stable and metabolically inert compound.