Two-stage thermal unfolding of [Cys55]-substituted Cro repressor of bacteriophage lambda.
It has been shown by scanning calorimetry and 1H NMR spectroscopy that thermal denaturation of mutant lambda phage cro repressor in which Val55 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 degrees 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.
Gitelson
G I
GI
Institute of Protein Research, Academy of Sciences of the USSR, Pushchino, Moscow Region.
Griko Yu
V
V
Kurochkin
A V
AV
Rogov
V V
VV
Kutyshenko
V P
VP
Kirpichnikov
M P
MP
Privalov
P L
PL
D010582:Bacteriophage lambda / Q000235:genetics*; D002152:Calorimetry, Differential Scanning / Q000379:methods; D003545:Cysteine; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics; D005813:Genes, Synthetic; D011489:Protein Denaturation; D015202:Protein Engineering; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics*; D014157:Transcription Factors / Q000737:chemistry; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D003545:Cysteine