Author/Editor     Kranjc, Zdenka; Lapanje, Savo; Poklar, Nataša
Title     Circular dichroic studies of thermal denaturation and denaturation by urea and alkylureas of human serum albumin
Type     članek
Source     Acta Chim Slov
Vol. and No.     Letnik 41, št. 3
Publication year     1994
Volume     str. 279-94
Language     eng
Abstract     The thermal denaturation of human serum albumin was investigated by measurement of circular dichroism (CD). On the basis of CD spectra secondary structure in the temperature range 25 - 85 degrees C was calculated. Solvent denaturation of the same protein by urea and some alkylureas (methyl-, ethyl- and N.N'-dimethylurea) was also studied by the sametechnique and secondary structure in 0 - 9 M solutions was ascertained. The results obtained indicate dependence of molar ellipticity on the alkyl group in urea molecule. Moreover, by using the data obtained and the assumption of two-state transition native - denatured protein, a thermodynamic analysis of the process is feasible and apparent thermodynamic quantities. Gibbs free energy, enthalphy and entropy of transition were obtained. Comparison of these values with those obtained by calorimetry shows that the apparent quantities are much smaller which indicates that the thermal denaturation of human serum albumin in water is a multi-state transition.
Descriptors     SERUM ALBUMIN
CIRCULAR DICHROISM
PROTEIN DENATURATION
UREA
TEMPERATURE
THERMODYNAMICS
PROTEIN STRUCTURE, SECONDARY