Catalytic properties and electrostatic potential of charged immobilized enzyme derivatives. Pyruvate decarboxylase attached to cationic polystyrene beads of different charge densities.

Pyruvate decarboxylase has been covalently attached to positively charged macroporous polystyrene resins. The changes in the functional behaviour of the enzyme resulting from the electrostatic interaction of the cationic carrier polymer and the anionic substrate have been studied as function of the fixed charge concentration of the carrier. The findings confirm the connection of two widely used theoretical expressions relating electrostatic parameters with Michaelis constants.