Biomaterial Database

A fluorescence study of conformational changes induced by substrate and temperature in bovine liver thiosulfate sulfurtransferase. 1982

Z Wasylewski, and P M Horowitz

Structural transitions occurring in the range of 0-50 degrees C have been detected and studied in the enzyme thiosulfate sulfurtransferase (thiosulfate:cyanide sulfurtransferase, EC 2.8.1.1) by investigating both the intrinsic protein fluorescence and the fluorescence of covalently bound probes. The intrinsic fluorescence of the enzyme decreases sharply at 27 degrees C and the magnitude of this quenching is smaller for the sulfur-substituted enzyme (ES) than for the free enzyme (E), both of which are obligatory catalytic intermediates. The effect with ES is fully reversible and almost completely so with E. Fluorescence depolarization sudies with thiosulfate sulfurtransferase labeled at a number of different sites with the fluorosphore dimethylaminonaphthalene show a sharp increase in the polarization starting at 27 degrees C when the temperature/viscosity ratio is varied with temperature and no transition when the ratio is varied with glycerol. Enzyme activity show no transition at 20 degrees C but falls abruptly above 40 degrees C. Under the appropriate conditions, the 27 degrees C transition will lead to association of thiosulfate sulfurtransferase molecules and the appearance of turbidity. Both activity and fluorescence measurements support the idea that the ES form is significantly more stable than the E form. These results may result from changes in the interactions between the structural domains into which the single polypeptide chain of thiosulfate sulfurtransferase is folded.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
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
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D003619	Dansyl Compounds	Compounds that contain a 1-dimethylaminonaphthalene-5-sulfonyl group.	Dimethylaminonaphthalenesulfonyl Compounds,Compounds, Dansyl,Compounds, Dimethylaminonaphthalenesulfonyl
D004355	Drug Stability	The chemical and physical integrity of a pharmaceutical product.	Drug Shelf Life,Drugs Shelf Lives,Shelf Life, Drugs,Drug Stabilities,Drugs Shelf Life,Drugs Shelf Live,Life, Drugs Shelf,Shelf Life, Drug,Shelf Live, Drugs,Shelf Lives, Drugs
D005454	Fluorescence Polarization	Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.	Anisotropy, Fluorescence,Fluorescence Anisotropy,Polarization, Fluorescence,Anisotropies, Fluorescence,Fluorescence Anisotropies,Fluorescence Polarizations,Polarizations, Fluorescence
D005456	Fluorescent Dyes	Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.	Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D013466	Sulfurtransferases	Enzymes which transfer sulfur atoms to various acceptor molecules. EC 2.8.1.	Sulfurtransferase