Phosphoglycerate dehydrogenase from soybean nodules. Partial purification and some kinetic properties [Glycine max]

Phosphoglycerate dehydrogenase (EC 1.1.1.95), an enzyme believed to be involved in the synthesis of serine, an intermediate in ureide biosynthesis, has been purified about 200-fold from nodules of soybean (Glycine max L. Merr. cv Amsoy 71). The reaction was reversible and exhibited a strong pH depen...

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Bibliographic Details
Published in:Plant physiology (Bethesda) 1983-03, Vol.71 (3), p.658-661
Main Authors: Boland, M J, Schubert, K R
Format: Article
Language:English
Subjects:
Biosynthesis
Dehydrogenases
Enzymes
Epicotyls
Glycine max
Liver
Nodules
Oxidation
Peas
phosphoglycerate dehydrogenase
Purines
Soybeans
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Summary:Phosphoglycerate dehydrogenase (EC 1.1.1.95), an enzyme believed to be involved in the synthesis of serine, an intermediate in ureide biosynthesis, has been purified about 200-fold from nodules of soybean (Glycine max L. Merr. cv Amsoy 71). The reaction was reversible and exhibited a strong pH dependence with optima of 9.4 and 6.1 for the forward and reverse reactions. The Km values for the forward reaction were 0.25 millimolar for NAD+ and 0.29 millimolar for D-3-phosphoglycerate at pH 9.4, while those for the reverse reaction were 12 μM for NADH and 0.15 millimolar for 3-phosphohydroxypyruvate at pH 7.5. NADPH functioned as an alternate reductant with a Km of 0.15 millimolar. Product inhibition for the reverse reaction was competitive for NAD+ with respect to NADH and noncompetitive for phosphoglycerate with respect to phosphohydroxypyruvate. Phosphoglycerate dehydrogenase activity was dependent on inorganic ions and was not inhibited by serine.
ISSN:0032-0889
1532-2548
DOI:10.1104/pp.71.3.658