Glyceraldehyde 3-phosphate dehydrogenase ofScenedesmus obliquusthe effect of ATP on the dithiothreitol-promoted induction of NADPH-dependent activity

✍ Scribed by Sandra Woodrow; Roy Powls

• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 333 KB
• Volume: 120
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00409105

✦ Synopsis

Incubation of hexadecameric glyceraldehyde 3-phosphate dehydrogenase of Scenedesmus obliquus with dithiothreitol caused a transient increase in NADPH-dependent activity. When ATP was also included in the incubation, the induced NADPHdependent activity was stabilised. The rate of induction of NADPH-dependent activity increased hyperbolically with respect to ATP concentration. The effect of binding of ATP to the enzyme was two-fold; not only did it stimulate the dithiothreitol-promoted formation of an enzyme species with high NADPH-dependent activity it also prevented the inactivation of this species. The high concentration of ATP required for the stimulation of the NADPH-dependent activity compared with those for NADPH suggest that activation by ATP is unlikely to be of physiological significance.