Biomaterial Database

Inactivation and conformational changes of yeast alcohol dehydrogenase in trifluoroethanol solutions. 1998

Y Yang, and X S Zhang, and H M Zhou

Department of Biological Science and Biotechnology, Tsinghua University, Beijing, 100084, P. R. China.

Conformational changes of yeast alcohol dehydrogenase in trifluoroethanol solutions have been followed by fluorescence emission and circular dichroism spectroscopy. At low concentration (less than 5%), trifluoroethanol shows a reversible inhibition competitive to ethanol and noncompetitive to NAD+. The inhibition constants for native and structural-zinc-removed yeast alcohol dehydrogenase were 5.8 and 1.1 mM, respectively, suggesting that the active site becomes more flexible after the structural zinc is removed. At higher trifluoroethanol concentrations the enzyme was irreversibly inactivated. Comparison of inactivation and conformational changes of yeast alcohol dehydrogenase denatured in trifluoroethanol solutions shows that the extent of inactivation is larger than the extent of conformational changes at the same trifluoroethanol concentration. The results obtained from circular dichroism spectra show that the presence of trifluoroethanol can induce the formation of secondary structure of the enzyme.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
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
D000426	Alcohol Dehydrogenase	A zinc-containing enzyme which oxidizes primary and secondary alcohols or hemiacetals in the presence of NAD. In alcoholic fermentation, it catalyzes the final step of reducing an aldehyde to an alcohol in the presence of NADH and hydrogen.	Alcohol Dehydrogenase (NAD+),Alcohol Dehydrogenase I,Alcohol Dehydrogenase II,Alcohol-NAD+ Oxidoreductase,Yeast Alcohol Dehydrogenase,Alcohol Dehydrogenase, Yeast,Alcohol NAD+ Oxidoreductase,Dehydrogenase, Alcohol,Dehydrogenase, Yeast Alcohol,Oxidoreductase, Alcohol-NAD+
D000431	Ethanol	A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in ALCOHOLIC BEVERAGES.	Alcohol, Ethyl,Absolute Alcohol,Grain Alcohol,Alcohol, Absolute,Alcohol, Grain,Ethyl Alcohol
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D012996	Solutions	The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)	Solution
D014270	Trifluoroethanol	A non-aqueous co-solvent that serves as tool to study protein folding. It is also used in various pharmaceutical, chemical and engineering applications.	Trifluoroethyl Alcohol,2,2,2-Trifluoroethanol,Alcohol, Trifluoroethyl