Dimethylallyltryptophan synthetase

It has been found that elymoclavine (128) inhibits dimethylallyltryptophan synthetase, and the mechanism is one of feedback inhibition.46... 

Experiments have been carried out with elymoclavine (73) in whole cells and protoplasts of Claviceps strain SD 58 levels of dimethylallyltryptophan synthetase, the first enzyme in ergot alkaloid biosynthesis, were measured.64 The results that were obtained provide strong evidence that there is end-product regulation of the synthesis of alkaloids in vivo and that it involves feedback inhibition end-product repression of the synthesis of enzymes appears to be of lesser importance. 

Fig. 3. Induction of Dimethylallyltryptophan Synthetase by Tryptopahn and Tryptophan Analogs.

Dimethylallyltryptophan synthetase is so far the only enzyme in the ergoline biosynthetic pathway which has been highly purified (4). 

Fig. 10. Dimethylallyltryptophan synthetase levels in dialyzed cell-free extracts of normal and elymoclavine-treated protoplasts of Clsviceps Strain SD 58...

Maier, W. and D. Groger, Dimethylallyltryptophan-Synthetase in Claviceps, Biochem. Physiol. Pflanzen, 170, 9-15 (1976). 

Dimethylallyltryptophan synthetase (systematic name dimethylallyl-pyrophosphate L-tryptophan dimethylallyltransferase) was isolated by Heinstein et al. (1971). The enzyme was purified to homogeneity from mycelia of Claviceps strain SD 58 (Lee et al., 1976). The enzyme is a single polypeptide chain with molecular weight 73,000. It is activated by... 

The biosynthesis of ergot alkaloids is initiated by prenyla-tion of tryptophan with dimethylallyl pyrophosphate (DMAPP) to yield 4-dimethylallyltryptophane (DMAT) (4) (Fig. 35.2) (Floss, 1980). This alkylation step is believed to be rate limiting, and the enzyme that catalyzes this reaction, DMAT synthetase, has been purified more than 60 times (Maier and Groger, 1976 Waller and Dermer, 1981). The enzyme appears to be specific for L-tryptophan and is inhibited by agroclavine (2) and elymoclavine (5) the end products of the reaction. 

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