Premium
Two‐stage thermal unfolding of [Cys 55 ]‐substituted Cro repressor of bacteriophage λ
Author(s) -
Gitelson G.I.,
Griko Yu.V.,
Kurochkin A.V.,
Rogov V.V.,
Kutyshenko V.P.,
Kirpichnikov M.P.,
Privalov P.L.
Publication year - 1991
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(91)81069-k
Subject(s) - mutant , dimer , repressor , bacteriophage , chemistry , crystallography , molecule , nuclear magnetic resonance spectroscopy , stereochemistry , biophysics , biochemistry , biology , gene , escherichia coli , organic chemistry , transcription factor
It has been shown by scanning calorimetry and 1 H NMR spectroscopy that thermal denaturation of mutant λ phage cro repressor in which Val 55 was substituted for Cys, proceeds in 2 stages in contrast to the wild type protein. At neutral pH values, an additional cooperative transition has been observed at about 100°C. Calorimetric measurements on the mutant and its tryptic fragment lead to the conclusion that the two‐stage character of thermal unfolding of the mutant is due to a disruption of an additional cooperative domain in the dimer molecule which is stabilized by the S–S crosslink.