Energetics of ribonuclease T1 structure.
The energetics of thermal denaturation of two isoforms of ribonuclease T1 (Gln25 and Lys25) in various solvents have been studied by differential scanning calorimetry. It has been shown that the thermal transition of both forms of RNase T1 is strongly affected by slow kinetics, which cause an apparent deviation of the transition from a simple two-state model. By decreasing the heating rate or increasing the transition temperature, the denaturation of RNase approaches an equilibrium two-state transition. This permits determination of the thermodynamic parameters characterizing unfolding of the native structure. These thermodynamic parameters were correlated with the structural features of protein. Analysis of different contributions to the stability of RNase T1 shows that van der Waals interactions and hydrogen bonding are the major contributors to the conformational stability of the protein.
Yu
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Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
Makhatadze
G I
GI
Pace
C N
CN
Privalov
P L
PL
D001236:Aspergillus oryzae / Q000201:enzymology; D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004795:Enzyme Stability; D004926:Escherichia coli; D006358:Hot Temperature; D006860:Hydrogen Bonding; D007700:Kinetics; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000737:chemistry; D006163:Ribonuclease T1 / Q000737:chemistry*; D013816:Thermodynamics
D011994:Recombinant Proteins; D006163:Ribonuclease T1