Detail of "1954-45-6"

Reference

Action of tryptophan analogs in Saccharomyces cerevisiae

Action of tryptophan analogs in Saccharomyces cerevisiae. Miozzari, Giuseppe; Niederberger, Peter; Huetter, Ralf (Mikrobiol. Inst., ETH, Zurich, Switz.). Arch. Microbiol., 115(3), 307-16 (English) 1977. CODEN: AMICCW. ISSN: 0302-8933. DOCUMENT TYPE: Journal CA Section: 3 (Biochemical Interactions) In S. cerevisiae, 4-methyltryptophan [1954-45-6] decreased protein synthesis and depressed tryptophan [73-22-3] enzymes despite the presence of high internal levels of tryptophan. This inhibition was only obsd. in a mutant with increased permeability to the analog. This analog may interfere with the charging of tryptophan onto tRNA. 5-Methyltryptophan [154-06-3] caused false feedback inhibition of anthranilate synthase [9031-59-8], the 1st enzyme of the tryptophan pathway. This inhibited the further synthesis of tryptophan and resulted in tryptophan limitation, growth inhibition, and depression of the enzymes. Derepression eventually allowed wild type cells to partially overcome the inhibitory effect of the analog. 5-Fluoroindole [399-52-0] was converted endogenously to 5-fluorotryptophan [154-08-5] by tryptophan synthase. Both endogenous and externally supplied 5-fluorotryptophan were incorporated into protein. This led to intoxication of the cells due to the accumulation of faulty proteins. 5-Fluorotryptophan also caused feedback inhibition of anthranilate synthase and decreased the synthesis of tryptophan. Indoleacrylic acid [1204-06-4] inhibited the conversion of indole to tryptophan by tryptophan synthase. This resulted in a depletion of the tryptophan pool which, in turn, caused growth inhibition and derepression of the tryptophan enzymes. The use of these tryptophan analogs provides the means for specific alterations of the flux through the tryptophan pathway at different steps.

Selection of cell lines of Catharanthus roseus with increased tryptophan decarboxylase activity

Selection of cell lines of Catharanthus roseus with increased tryptophan decarboxylase activity. Sasse, Florenz; Buchholz, Marita; Berlin, Jochen (Ges. Biotechnol. Forsch. m.b.H., Braunschweig D-3300, Fed. Rep. Ger.). Z. Naturforsch., C: Biosci., 38C(11-12), 916-22 (English) 1983. CODEN: ZNCBDA. ISSN: 0341-0382. DOCUMENT TYPE: Journal CA Section: 11 (Plant Biochemistry) Section cross-reference(s): 16 Cell lines of C. 9042-64-2 and 1954-45-6 are also in the experiment. roseus were selected for resistance to 4-methyltryptophan (4-MT) to obtain strains with increased activities of tryptophan decarboxylase (TDC). 4-MT is a substrate for TDC and is detoxified by this enzyme. All 4-MT resistant cell lines showed increased TDC activity (3-10-fold) and higher accumulation of tryptamine (3-5-fold). Two of these cell lines with increased TDC activity accumulated indole alkaloids in the growth medium, whereas in wild type cultures and other resistant cell lines this was not the case. All the cell lines obtained were not only resistant to 4-MT (20-70-times more than wild type cells) but were also cross-resistant to other tryptophan analogs which are not metabolized by TDC. Therefore, the resistance was not only due to a better detoxification of the analog. The selected cell lines also contained 2-6 times higher levels of L-tryptophan, but the feedback sensitivity of the anthranilate synthetase of the resistant cells was not altered. .