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. 1990 Nov;94(3):1492–1495. doi: 10.1104/pp.94.3.1492

Conversion of l-Sorbosone to l-Ascorbic Acid by a NADP-Dependent Dehydrogenase in Bean and Spinach Leaf 1

Mary W Loewus 1, Diana L Bedgar 1, Kazumi Saito 1,2, Frank A Loewus 1
PMCID: PMC1077405  PMID: 16667860

Abstract

An NADP-dependent dehydrogenase catalyzing the conversion of l-sorbosone to l-ascorbic acid has been isolated from Phaseolus vulgaris L. and Spinacia oleracea L. and partially purified. It is stable at −20°C for up to 8 months. Molecular masses, as determined by gel filtration, were 21 and 29 kilodaltons for bean and spinach enzymes, respectively. Km for sorbosone were 12 ± 2 and 18 ± 2 millimolar and for NADP+, 0.14 ± 0.05 and 1.2 ± 0.5 millimolar, for bean and spinach, respectively. Lycorine, a purported inhibitor of l-ascorbic acid biosynthesis, had no effect on the reaction.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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