Biomaterial Database

[Effect of monovalent cations on the catalytic and spectral properties of tyrosine-phenol-lyase from Citrobacter intermedius]. 1985

I V Miagkikh, and T V Demidkina

The action of monovalent cations Li+, Na+, K+, Rb+, Cs+, NH4+ on catalytic and physico-chemical properties of bacterial tyrosine--phenol-lyase was investigated. It was shown that K+, Rb+, Cs+, NH4+ were the noncompetitive activators of the enzyme, Na+ was an inhibitor, Li+ did not influence the catalytic activity. The values of KA and Vmax were determined for the activators in the reaction of alpha, beta-elimination of L-tyrosine. Monovalent cations affect the absorption and CD spectra of the enzyme and its complex with the quasi-substrate--L-alanine. It was suggested that an activation of tyrosine phenollyase by monovalent cations was connected with the increase of the active protonated form of the holoenzyme (lambda max 420 mm) induced by the cations-activators.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008190	Lyases	A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.	Desmolase,Desmolases,Lyase
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D002414	Cations, Monovalent	Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.	Monovalent Cation,Cation, Monovalent,Monovalent Cations
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D002954	Citrobacter	A genus of gram-negative, rod-shaped enterobacteria that can use citrate as the sole source of carbon.
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
D014447	Tyrosine Phenol-Lyase	An enzyme that catalyzes the cleavage of tyrosine to phenol, pyruvate, and ammonia. It is a pyridoxal phosphate protein. The enzyme also forms pyruvate from D-tyrosine, L-cysteine, S-methyl-L-cysteine, L-serine, and D-serine, although at a slower rate. EC 4.1.99.2.	beta-Tyrosinase,Phenol-Lyase, Tyrosine,Tyrosine Phenol Lyase,beta Tyrosinase