Mechanism of the enzymic elimination of ammonia from 3-substituted aspartic acids by 3-methylaspartase
Abstract
Kinetic experiments with 3-methylaspartase, using aspartic, 3-methylaspartic, and 3-ethylaspartic acid and the appropriate C-3 deuteriated isotopomers as substrates, reveal that C(3)–H bond cleavage is partially rate-limiting for 3-methylaspartic acid, much less rate-limiting for 3-ethylaspartic acid, and not rate-limiting at all for aspartic acid.