Globular proteins calorimetric studies

Privalov, P.L., N.N. Khechinashvili, and B.P. Atanasov. 1971. Thermodynamic analysis of thermal transitions in globular proteins. I. Calorimetric study of chy-motrypsinogen, ribonuclease and myoglobin. Biopolymers 10 1865-1890. 

Privalov, P.L. and N.N. Khechinashvili. 1974. A thermodynamic approach to the problem of stabilization of globular protein structure a calorimetric study. J Mol Biol 86 665-684. 

If the process follows the two-state model, then the calorimetric enthalpy, A //, the calorimetrically obtained van t Hoff enthalpy, AHeff, and, where optical measurements have been made, the optical van t Hoff enthalpy, AHuh, should agree. Figure 16.9 shows the ratio, AH /AHvi obtained from denaturation studies of five globular proteins under various conditions, plotted against the corresponding denaturation temperature. This plot shows that the ratio is very close to unity. Similar results for numerous other small globular proteins have been obtained and most show a similar relationship. It is clear, however, that the ratio is closer to 1.05 than to 1. Freire and Biltonen11 have shown from a consideration of the partition functions associated with the native and the denatured state that this relative excess is... 

Calorimetric studies have established several general features of protein denaturation.12 13 14 For small globular proteins, the denaturation process is well represented by a two-state process,... 

One of the key observations resulting from calorimetric studies of the denaturation of globular proteins is that both AH0 and AS0 of denaturation, when normalized to the number of amino acid residues in the protein (or the molecular weight), converge to common values at specific temperatures when extrapolated under the assumption of constant ACp (Privalov and Khechinashvili, 1974 Privalov, 1979 Pri-... 

An extensive series of review papers and research papers has been published by Tanford on protein denaturation. The stability of protein structure has been discussed in several articles by Privalov, with particular attention paid to the small globular proteins. Conformational behavior is dependent on the inter- and intramolecular forces experienced by these macromolecules. Weakly polar interactions in proteins play an important role and have been discussed by Burley and Petsko. Gurd and Rothgeb have described the motions observed in these nonquiescent macromolecules. Studies of the calorimetrically determined dynamics of complex unfolding transitions in proteins have been reviewed by Freire et al ... 

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