Significance of CoA-transferase in the reaction of maleate with amino acids and proteins.

Maleate reacts, in the presence of acetoacetyl-CoA and CoA-transferase with amino acids containing no sulphydryl groups. The physico-chemical properties of the reaction products are the same as those of the derivatives obtained in the reaction of amino acids with maleic anhydride, which indicates that the amino groups became acylated. In the presence of the transferase system, maleate also reacts with such proteins as histone IIA, cytochrome c and albumin. The reaction also occurs after blocking SH groups, thus it could involve amino groups as well. The reacting agent is not maleate itself but a product of the reaction of maleate with acetoacetyl-CoA, catalysed by the transferase, i.e. maleyl-CoA.