Abstract

84
D. Appleton and F. J. Leeper
"Deuterium Isotope Effects on Porphobilinogen Synthesis Catalysed by 5-Aminolaevulinic Acid Dehydratase"
Bioorg. Med. Chem. Lett.,1996, 6, 1191-1194. Full Text

Deuteriation of 5-aminolaevulinic acid (ALA) at C-5 has no effect on the rate of porphobilinogen synthesis by ALA dehydratase from Bacillus subtilis but deuteriation at C-3 gave isotope effects on k_cat and k_cat/K_M of 3.4 and 2.3 respectively. Reisolated ALA after 50% reaction shows no significant loss of deuterium at C-3, indicating that it is probably the first deprotonation at this carbon which is rate-determining.

Previous abstract

Next abstract