Soluble complexes of trypsin with synthetic polybases

1. It was shown that trypsin forms complexes with vinylpyrrolidone-vinylamine copolymers, polyvinylimidazole, and poly(2-methyl-5-vinylpyridine) at a pH below its isoelectric point. The role of electrostatic interaction in the complexing process was ascertained. 2. The bonding with polybases of variable structure does not lower the trypsin activity and does not involve its native structure. A stabilization of trypsin under the conditions of the autocatalytic process, and also during heat and acid-base denaturation, is observed here. 3. The stabilizing capacity of the polymers is substantially higher than that of the corresponding monomeric bases (imidazole and N-ethylimidazole). 4. A method was proposed for approximately estimating the complexing constants in the investigated systems. The effect of the pH of the medium on the bonding constant of trypsin with poly(N-vinylimidazole) was studied.