Dithiothreitol: An inhibitor of glucose-6-phosphate-dehydrogenase activity in leaf extracts and isolated chloroplasts.
The activity of glucose-6-phosphate dehydrogenase (G-6-P-DH; D-glucose 6-phosphate: NADP oxidoreductase, EC 1.1.1.49) in leaf extracts of barley and spinach can be decreased 20-35% by incubation of the leaf extracts with dithiothreitol (DTT). This inhibition is complete within 2 min at 0°C and is reversible. The DTT-inhibited portion of G-6-P-DH activity in leaf extracts is probably that portion of leaf enzyme inhibited during illumination, and evidence has been obtained that this activity is located in the chloroplasts.
Department of Botany, University of Queensland, St. Lucia, Queensland, Australia.
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Johnson