Tryptophane Metabolism

Bauguess, Lyle C.; Berg, Clarence P.

doi:10.1016/s0021-9258(18)75437-9

Cited by 5 publications

(1 citation statement)

References 8 publications

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“…165-167°(capillary tube) was a specimen specially synthesized by Prof. C. P. Berg [cf. Baugess & Berg, 1934] to whom we wish to express our deep gratitude for his generous gift and help.…”

Section: Methodsmentioning

confidence: 99%

The coli-tryptophan-indole reaction

Baker

Happold

1940

Biochemical Journal

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THE reaction whereby l-tryptophan is broken down to indole by E. coli has been studied independently by Woods [1935, 1, 2] and by Happold & Hoyle [1935]. Woods worked with washed viable cells of the organism, whereas the latter investigators used suspensions killed in various ways but which, nevertheless, retained the property of catalysing this reaction. By coincidence both investigations, although following different courses, included examination of a similar selection of those indole derivatives which, on the basis of various mechanisms suggested in the literature, should be intermediate stages in the breakdown. Both sets of data (obtained by different techniques) uniformly revealed failure to produce indole from such derivatives and thus effectively disproved the validity of current mechanisms which, after all, had been formulated solely on analogy to other degradations.Woods [1935, 2] also studied the kinetics of the reaction and showed that the process requires 5 atoms of oxygen, that the conversion of tryptophan into indole goes to completion, and that the rate of indole production is equal to the rate at which the tryptophan disappears. The reaction could be represented Cn1HL202N2+ 50 --C,H7N+NH3+H20+3CO2 and thus involves an over-all oxidation, deamination and decarboxylation. Whether these processes are effected simultaneously by different enzymes or by a single master enzyme which catalyses simultaneously a number of reactions associated with the fission and oxidative breakdown of the alanine side-chain is not known.The present communication describes an investigation in which the sidechain of tryptophan was modified systematically in an attempt to determine the structural features which are essential for the degradation of the molecule to indole by tryptophanase. The following derivatives have been tested with active enzyme systems: (C02H group modified) 1-tryptophan methyl ester hydrochloride, 1-oc-amino-f3-3-indolylpropionamide; (NH2 group modified) the phenylurethane, p-nitrobenzoyl-, and N-methylene-derivatives of l-tryptophan, methyl l-cx-methylamino-fl-3-indolylpropionatehydriodide,r-ac-methylamino-,-3-indolylpropionic acid, methyl-a-dimethylamino-/3-3-indolylpropionate methiodide;(whole side-chain modified but still containing groups of the type NH2 or NHR) fl-3-indolylethylamine, 3-indolylacetamide, 3-indolealdehyde semicarbazone, 3-indolylglyoxylamide and, finally r-3-indolylglycine, the next lower homologue of tryptophan.

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“…165-167°(capillary tube) was a specimen specially synthesized by Prof. C. P. Berg [cf. Baugess & Berg, 1934] to whom we wish to express our deep gratitude for his generous gift and help.…”

Section: Methodsmentioning

confidence: 99%