Changing kinetic properties of glucose-6-phosphate dehydrogenase from pea chloroplasts during photosynthetic induction

Conference · Wed Apr 01 04:00:00 EST 1987 · Plant Physiol., Suppl.; (United States)

OSTI ID:6076228

Yuan, X; Anderson, L E

The first enzyme of the oxidative pentose phosphate pathway, glucose-6-P dehydrogenase (EC 1.1.1.49), is inactivated when pea chloroplasts are irradiated. They have examined the kinetics of light inactivation of glucose-6-P dehydrogenase in intact chloroplasts during photosynthetic induction and the kinetic parameters of the active (dark) and less active (light) form of the dehydrogenase. Light inactivation of the dehydrogenase is rapid and occurs before photosynthetic O/sub 2/ evolution is measureable in intact chloroplasts. Likewise dark activation is quite rapid. The major change in the kinetic parameters of glucose-6-phosphate dehydrogenase is in maximal velocity. This light inactivation probably prevents operation of a futile cycle involving glucose-6-P, NADPH and oxidative and reductive pentose phosphate pathway enzymes.

• Research Organization: Univ. of Illinois, Chicago
• OSTI ID: 6076228
• Report Number(s): CONF-8707108-
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 83:4
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHLOROPLASTS
ELECTROMAGNETIC RADIATION
ENZYME INDUCTION
ENZYMES
GENE REGULATION
HEMIACETAL DEHYDROGENASES
KINETICS
LEGUMINOSAE
METABOLISM
MICROORGANISMS
OXIDOREDUCTASES
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PISUM
PLANTS
RADIATIONS
REACTION KINETICS
RHIZOBIUM
SYNTHESIS
VISIBLE RADIATION