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Reduced‐denatured ribonuclease A is not in a compact state
Author(s) -
Nöppert Angela,
Gast Klaus,
Müller-Frohne Marlies,
Zirwer Dietrich,
Damaschun Gregor
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00048-8
Subject(s) - random coil , circular dichroism , guanidine , ribonuclease , denaturation (fissile materials) , chemistry , crystallography , protein secondary structure , hydrochloride , native state , dithiothreitol , enzyme , rna , biochemistry , nuclear chemistry , gene
Dynamic light scattering and circular dichroism experiments were performed to determine the compactness and residual secondary structure of reduced and by 6 M guanidine hydrochloride denatured ribonuclease A. We find that reduction of the four disulphide bonds by dithiothreitol at 20°C leads to total unfolding and that a temperature increase has no further effect on the dimension. The Stokes' radius of ribonuclease A at 20°C is R s = (1.90 ± 0.04) nm (native) and R s = (3.14 ± 0.06) nm (reduced‐denatured). Furthermore, circular dichroism spectra do not indicate any residual secondary structure. We suggest that reduced‐denatured Ribonuclease A has a random coil‐like conformation and is not in a compact denatured state.