The Kinetics of Protein Denaturation

Abstract

THE generally accepted view of the heat coagulation of proteins is that of Hardy [1899], who concludes that the process takes place in two stages, the first of which is a preliminary change in the chemical structure of the protein. This stage is termed "denaturation" and is followed by a purely physical process-" flocculation." While Lepeschkin [1922] is of the opinion that flocculation is not entirely physical in nature but to some extent chemical, it is generally agreed that in the presence of electrolytes the second stage takes place at a much more rapid rate than the preliminary stage of denaturation and hence by working in solutions always containing a little electrolyte the kinetics of the heat denaturation of proteins may be studied. That the presence of electrolyte is necessary for the final flocculation is shown by the observation of Aronstein [1874] and Heinsius [1874] that in the absence of electrolytes a protein solution may be heated without flocculation, but that if salt be added after cooling flocculation takes place.