S-Ethyl dipropylthiocarbamate (EPTC) and 2,2-dichloro- N,N-di-2-propenylacetamide (Dichlormid) inhibitions of synthesis of acetyl-coenzyme A derivatives

Abstract

[2- 14C]Acetate incorporation into acetyl-coenzyme A (acetyl-CoA) in wheat ( Triticum aestivum L. cv Stacy) chloroplasts was inhibited by S-ethyl dipropylthiocarbamate (EPTC, 0.01 μ M) and the inhibition was reversed by 90 μ M acetate. [2- 14C]Pyruvate was converted to acetyl-CoA by the pyruvate dehydrogenase complex (PDC) in wheat chloroplasts and the conversion was inhibited by EPTC (0.01 μ M). The inhibition was reversed by 90 μ M pyruvate. Production of NADH by wheat (cv. Holly) mitochondrial PDC was inhibited 10% by 3.3 10 −14 M EPTC and 90% by 0.33 μ M EPTC. Mitochondrial 2-oxoglutarate dehydrogenase complex activity was inhibited 65% by 0.033 μ M EPTC. Dichlormid (2,2-dichloro- N,N-di-2-propenylacetamide, 0.01 μ M) inhibited the incorporation of [2- 14C]acetate into wheat chloroplast acetyl-CoA and the inhibition was reversed by 90 μ M acetate. Dichlormid (0.01 μ M) also inhibited the chloroplastic conversion of [2- 14C]pyruvate into acetyl-CoA and partially reversed the inhibition by EPTC (0.1 μ M) of conversion of [2- 14C]pyruvate to acetyl-CoA.