| Abstract: | Analysis of the proteolytic degradation of the native protein structure carried out by the comparison of the temperature dependence of the hydrogen exchange and proteolytic splitting rates of the hen egg-white lysozyme and human Hb and apoHb. Acceleration of the burst-like (all or none) proteolytic degradation in the high temperature range is provided by the intensification of the global fluctuations with overall unfolding revealed by hydrogen exchange. For Hb and apoHb the rate of burst-like proteolytic degradation and hydrogen exchange weakly depends on temperature in the range, where hydrogen exchange reveals only local fluctuations of the native protein structure. The splitting of the two proteins proceeds by the selfaccelerated burst-like mechanism with the initial rate-limiting single cleavage owing to the local fluctuation of the native structure. The local fluctuations play important role also upon the intracellular burst-like degradation of native proteins. |
