The Tryptophanase from Escherichia coli K12
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چکیده
منابع مشابه
Escherichia coli tryptophanase in the enteric environment.
The activity of the enzyme tryptophanase in the enteric environment was investigated to elucidate the significance of the enzyme in the metabolism of Escherichia coli. The tryptophanase activity, tryptophan content, and indole concentration as well as the numbers of E. coli were determined in the intestinal and fecal contents of conventional, germ-free, and monocontaminated axenic laboratory mi...
متن کاملEssential arginine residues in tryptophanase from Escherichia coli.
Tryptophanase from Escherichia coli B/1t7-A is inactivated by the arginine-specific reagent, phenylglyoxal, in potassium phosphate buffer at pH 7.8 AND 25 degrees. Apo- and holoenzyme are inactivated at the same rate, and inactivation of both is correlated with modification of 2 arginine residues/tryptophanase monomer. Substrate analogs having a carboxyl group protect the holoenzyme against bot...
متن کاملRepression of Tryptophanase Synthesis in Escherichia Coli.
Beggs, William H. (University of Cincinnati, Cincinnati, Ohio), and Herman C. Lichstein. Repression of tryptophanase synthesis in Escherichia coli. J. Bacteriol. 89:996-1004. 1965.-The nature of the glucose effect on tryptophanase in Escherichia coli (Crookes) was investigated to test the catabolite-repression hypothesis. Under static conditions of growth in the presence of 0.005 m glucose, try...
متن کاملKinetic and equilibrium studies on the activation of Escherichia coli K12 tryptophanase by pyridoxal 5'-phosphate and monovalent cations.
An improved purification of Escherichia coli K12 tryptophanase is presented. It is shown that the apoenzyme crystals, oxidized by exposure to air, can be reactivated by treatment with a reducing agent. The titration of sulfhydryl groups shows that four --SH groups are exposed and two are masked per protomer. The influence of two effectors, monovalent cations and the coenzyme pyridoxal 5'-phosph...
متن کاملKinetic and Equilibrium Studies on the Activation of Escherichia coli K12 Tryptophanase by Pyridoxal S-Phosphate and Monovalent Cations *
An improved purification of Escherichia coli K12 tryptophanase is presented. It is shown that the apoenzyme crystals, oxidized by exposure to air, can be reactivated by treatment with a reducing agent. The titration of sulfhydryl groups shows that four -SH groups are exposed end two are masked per protomer. The influence of two effecters, monovalent cations and the coenzyme pyridoxal S-phosphat...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1974
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(19)42836-6