“…Many examples are known in which a mechanism-dependent enzyme inhibition occurs when a ß substituent of an inhibitor can be eliminated to form a Schiff base of a-aminoacrylate or a related ,/3-unsaturated amino acid or amine (step 1 of Scheme III; Miles & Meister, 1967;Relyea et al, 1974;John 6 Fasella, 1969; Fowler & John, 1972, 1981; Silverman & Abeles, 1976, 1981Soper et al, 1977;Soper & Manning, 1978;Morino et al, 1974; Wang et al, 1981;Kallio et al, 1981;Bey, 1981). It has generally been assumed, without any real proof, that inactivation of the enzyme is a result of addition of a nucleophilic group from the enzyme to the ß carbon of the double bond as indicated by the reaction marked with the X in Scheme III.…”