Biomaterial Database

Denaturation behavior of alpha-chymotrypsinogen A in urea and alkylurea solutions: fluorescence studies. 1994

N Poklar, and G Vesnaver, and S Lapanje

Department of Chemistry, University of Ljubljana, Slovenia.

The solvent denaturation of alpha-chymotrypsinogen (alpha-ctg A) in aqueous solution of urea, methyl-, N,N'-dimethyl-, ethyl-, propyl- and butylurea was studied by fluorescence measurements. Data were analyzed on the assumption of a two-state approximation to obtain the apparent equilibrium constant, Ku and the apparent Gibbs free energy of transition delta G0u. It has been observed that alkyl-substitution of urea significantly lowers the denaturant concentration needed to denature alpha-ctg A at 25 degrees C. Denaturation was accompanied by the red shift of emission maxima, the increase of the half-width of the fluorescence spectra, the increase of the fluorescence intensity, and the decrease of the fluorescence polarization. The differences of these fluorescence parameters observed for alpha-ctg A in alkylureas and urea can be ascribed to different unfolded states of the protein in different denaturant solutions. Minor differences in the extent of unfolding were confirmed by size-exclusion chromatography.

UI	MeSH Term	Description	Entries
D008782	Methylurea Compounds	Urea compounds which are substituted with one or more methyl groups.	Compounds, Methylurea
D011489	Protein Denaturation	Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.	Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D011498	Protein Precursors		Precursors, Protein
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
D002627	Chemistry, Physical	The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.	Physical Chemistry,Chemistries, Physical,Physical Chemistries
D002845	Chromatography	Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.	Chromatographies
D002919	Chymotrypsinogen		Alpha-Chymotrypsinogen,Chymotrypsinogen A,Chymotrypsinogen beta,Alpha Chymotrypsinogen,beta, Chymotrypsinogen
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
D005470	Fluorometry	An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.	Fluorimetry,Fluorometric Analysis,Analysis, Fluorometric