Coenzyme A- and NADH-dependent esterase activity of methylmalonate semialdehyde dehydrogenase

Academic Article

Abstract

  • Methylmalonate semialdehyde dehydrogenase purified to homogeneity from rat liver possesses, in addition to its coupled aldehyde dehydrogenase and CoA ester synthetic activity, the ability to hydrolyze p-nitrophenyl acetate. The following observations suggest that this activity is an active site phenomenon: (a) p-nitrophenyl acetate hydrolysis was inhibited by malonate semialdehyde, substrate for the dehydrogenase reaction; (b) p-nitrophenyl acetate was a strong competitive inhibitor of the dehydrogenase activity; (c) NAD+ and NADH activated the esterase activity; (d) coenzyme A, acceptor of acyl groups in the dehydrogenase reaction, accelerated the esterase activity; and (e) the product of the esterase reaction proceeding in the presence of coenzyme A was acety;-CoA. These findings suggest that an S-acyl enzyme (thioester intermediate) is likely common to both the esterase reaction and the aldehyde dehydrogenase/CoA ester synthetic reaction. © 1992.
  • Digital Object Identifier (doi)

    Author List

  • Popov KM; Kedishvili NY; Harris RA
  • Start Page

  • 69
  • End Page

  • 73
  • Volume

  • 1119