Fumaraldehydic acid-induced inactivation of aspartase
Higashi, Y.; Ida, N.; Tokushige, M.
Biochemistry International 17(1): 103-109
1988
ISSN/ISBN: 0158-5231 PMID: 3142474 Document Number: 310163
Fumaraldehydic acid (FAA) induced a time-dependent inactivation of aspartase (L-aspartate ammonia-lyase, EC 4.3.1.1) from Escherichia coli at 30 degrees C and pH 7.4 following pseudo-first order kinetics. The rate of inactivation increased in proportion to the FAA concentration. In addition, the rate of inactivation increased, as the pH was increased. Determination of sulfhydryl groups showed that approximately one among 11 sulfhydryl groups was modified by FAA concomitant with the inactivation. L-Aspartate and fumarate protected the enzyme against FAA-inactivation, when Mg2+ ions were present. Unlike E. coli aspartase, P. fluorescens aspartase was not inactivated by FAA.