[Buffer capacity of polyproton substances].

Mathematical analysis of protolytic properties of a polyelectrolite with arbitrary set of stepwise dissotiation constants is carried out, based on disintegration of summary titration curves and buffer capacity for basic functions. It is demonstrated, that in some cases (for example, investigation of biomembranes and their components) simplified disintegration variants can be used. Buffer titration curve of biopolymers and biomembranes is a "buffer spectrum", the position of bands on the pH scale, their intensity and half-width being determined by the nature of the object (the quantity and quality of hydrophilic groups and the set of its conformation states). Sharp peaks of the buffer spectrum correspond to the conformation transition of the object, and their half-width on the pH scale determines the cooperative degree of each conformation transition. The mathematical analysis described is not specific to the formation of polyprotonic complex, and it can be used in investigation of the complex formation with any monodentant ligand. It is concluded that the method described can be used in the investigation of complex biomembranes and different processes, in which these membranes participate.