|
type |
Journal Article |
authors |
Hayashi, S.; Noguchi, T. |
title |
Response to light of a specific aminotransferase for delta- aminolevulinate formation in higher plants |
journal |
J Biol Chem |
Activity |
2.6.1.43 |
ui |
84061779 |
year |
(1983) |
volume |
258 |
number |
22 |
pages |
13693-6. |
| |
keywords |
Comparative Study |
abstract |
It is thought that the C-5 pathway is the major, possibly the sole, route for the formation of delta-aminolevulinic acid for the biosynthesis of tetrapyrroles, including chlorophylls, in higher plants; a route involving 4,5-dioxovalerate as an intermediate followed by transamination to delta-aminolevulinic acid has been supported as one of the C-5 pathways (Granick, S., and Beale, S. I. (1978) Adv. Enzymol. Relat. Areas Mol. Biol. 46, 33-203). A specific aminotransferase for L-alanine and 4,5-dioxovalerate was found in the cucumber seeds. In dark-grown cucumber seedlings, alanine:4,5- dioxovalerate aminotransferase activity in the transitional region between shoot and root was remarkably high compared with that in the cotyledons. The exposure of the dark-grown seedlings to illumination resulted in a rapid and dramatic increase in the activity only in this transitional region. In contrast, the enzyme in the cotyledons, stem, and roots did not respond to illumination. After a 27-h illumination, the enzyme activity in the transitional region was 100-fold higher than that in the cotyledons. Other aminotransferases assayed in the transitional region did not respond to illumination. Alanine:4,5- dioxovalerate aminotransferase in the transitional region was also specific for L-alanine and 4,5-dioxovalerate. |
last changed |
2002/11/12 16:17 |
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