L-Chlorosuccinate and L-methylsuccinate are substrates for succinic dehydrogenase, chlorofumarate and mesaconate being produced, respectively, by enzyme catalyzed dehydrogenation. The respective enantiomorphs, D-chlorosuccinate and L-methylsuccinate, are inhibitors of the enzyme and the stereospecificity of succinic dehydrogenase is thereby established. The enzyme exhibits a trans stereoselectivity, dehydrogenating erythro-3-deuterio-L-chlorosuccmate to 3-deuterio-chloro chlorofumarate. From the above facts the stereochemistry of the behavior of succinic acid in the enzyme substrate complex is deduced. KM values and K1 values for the new substrates under specified conditions are presented and E0' values at pH 7.3, 34° for the chlorosuccinate/chlorofumarate and methylsuccinate/mesaconate half-cells are 0.0462 volt and -0.0018 volt, respectively.
ASJC Scopus subject areas
- Colloid and Surface Chemistry