Properties of the glyceraldehyde-3-P dehydrogenase in heterocysts and vegetative cells of cyanobacteria |
| |
Authors: | H Papen G Neuer A Sauer H Bothe |
| |
Institution: | Botanical Institute, University of Cologne, Gyrhostrasse 15, D-5000 Cologne 41, F.R.G. |
| |
Abstract: | Abstract Glyceraldehyde-3-P dehydrogenase (GAPDH) in heterocysts and vegetative cells of 3 N2-fixing cyanobacteria was found to utilize both NAD+ and NADP+. The enzyme activity was enhanced by thiols (glutathione, reduced lipoic acid and dithiothreitol). GAPDH of the 3 cyanobacterial species was not activated by thioredoxin. Heterocysts have now been shown to possess all the enzymes of glycolysis and the tricarboxylic acid cycle to convert glyceraldehyde-3-phosphate (GAP) to oxoglutarate and glutamate. The GAPDH reaction is a major source for the generation of NADH, which is oxidized by a thylakoid-bound NADH:plastoquinone oxidoreductase in heterocysts. |
| |
Keywords: | Anabaena sp cyanobacterium heterocyst glyceraldehyde-3-P-dehydrogenase |
|
|