Original scientific paper

Interactions of a-Chymotrypsinogen A with Some Alkylureas

S. Lapanje ; Department of Chemistry and Chemical Technology, Edvard Kardelj University, Ljubljana, Yugoslavia
M. Simič ; Department of Chemistry and Chemical Technology, Edvard Kardelj University, Ljubljana, Yugoslavia
A. Pavlič ; Department of Chemistry and Chemical Technology, Edvard Kardelj University, Ljubljana, Yugoslavia

Abstract

The interactions of a-chymotrypsinogen A with urea, methyl-,
N,N'-dimethyl-, ethyl-, N,N'-diethyl-, and propylurea were studied
by means of calorimetry and circular dichroism. It has been found
that the enthalpies of interaction of the alkylureas, with the
exception of methylurea, with a-chymotrypsinogen A are distinctly
from those of urea. Thus the transfer of the protein from water to
aqueous urea and methylurea solutions is accompanied by release
of heat, · i.e., the overall reaction is exothermic, whereas the
transfer of the same protein to solutions of other alkylureas is
characterized by consumption of heat, i.e., the overall reaction
is endothermic. By examining the far UV CD spectra it can also
be concluded that the alkylureas are clearly less efficient denaturants
than urea. The difference in behavior reflects the presence
of the hydrophobic moiety in the urea molecule.

Keywords

Hrčak ID:

194313

URI

https://hrcak.srce.hr/194313

Publication date:

25.2.1982.

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