ISSN:
1432-072X
Keywords:
Candida maltosa
;
Glyphosate
;
Shikimate pathway
;
5-Enolpyruvylshikimate 3-phosphate synthase
;
5-Dehydroquinate synthase
;
3-Deoxy-D-arabino-heptulosonate 7-phosphate synthase
;
Enzyme inhibition
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The broad-spectrum herbicide glyphosate inhibits the growth of Candida maltosa and causes the accumulation of shikimic acid and shikimate-3-phosphate. Glyphosate is a potent inhibitor of three enzymes of aromatic amino acid biosynthesis in this yeast. In relation to tyrosine-sensitive 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase and dehydroquinate synthase, the inhibitory effect appears at concentrations in the mM range, but 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase is inhibited by micromolar concentrations of glyphosate. Inhibition of partially purified EPSP synthase reaction by glyphosate is competitive with respect to phosphoenolpyruvate (PEP) with a K i -value of 12 μM. The app. K m for PEP is about 5-fold higher and was 62 μM. Furthermore, the presence of glyphosate leads to derepression of many amino acid biosynthetic enzymes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00409776
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