title: Succinic semialdehyde dehydrogenase of wheat grain.
abstract: Succinic semialdehyde dehydrogenase (EC 1.2.1.16) was purified 74-fold from wheat grain (Triticum durum Desf.). The enzyme appears quite specific for succinic semialdehyde (SSA). Both NAD and NADP support the oxidation of the substrate, but the former is 7-fold more active than the latter. The optimum pH for activity is around 9; the enzyme is stable in the pH range 6-9 and retains its whole activity up to 40°C. The enzyme activity is strongly dependent on the presence of mercaptoethanol, other thiol compounds being much less effective. Kinetic data support the formation of a ternary complex between enzyme, substrate and coenzyme. The K m for SSA and for NAD are 7.4x10(-6) M and 2x10(-4) M, respectively. The molecular weight of the enzyme protein was estimated by gel-filtration to be about 130,000.
authors.affiliation: Institute of Botany, University of Pisa, Via Luca Ghini, 5, I-56100, Pisa, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Galleschi
authors.forename: M G
authors.initials: MG
authors.lastname: Tozzi
authors.forename: I
authors.initials: I
authors.lastname: Cozzani
authors.forename: C
authors.initials: C
authors.lastname: Floris