Factors influencing the activity of testicular hyaluronidase

Abstract

Listen

Translate article

1. 1. The influence of dilution and of addition of polyelectrolytes, mainly of macromolecular nature, on the activity of testicular hyaluronidase was studied. 2. 2. Two samples of hyaluronidase, i.e., a commercial preparation and a product purified fivefold by zone electrophoresis, served for this study. Enzyme activity was measured by two independent procedures, namely by the viscosity-reducing and by the turbidity-reducing methods. The latter technique has been modified and adapted for use at high enzyme dilutions. 3. 3. Upon dilution, hyaluronidase is transformed into an enzymically inactive form, recognizable by the progressive loss of specific activity. This phenomenon is due to a reversible dissociation of the active enzyme into inactive components. 4. 4. Dissociation of hyaluronidase can be reversed by the addition of polycations, in particular by poly- l-lysine, protamine, chitin, and 1,10-diaminodecane, in the order of decreasing potency. These substances are, therefore, activators of dilute hyaluronidase. 5. 5. Macromolecular polyanions, such as polystyrene sulfonate, heparin, sulfated pectic acid, polymethacrylate, amylopectin sulfate, and deoxyribonucleate are inhibitors of hyaluronidase. They act by sequestrating the activator and, hence, they promote dissociation of the enzyme into inactive components. The inhibition is of the “activator-competitive” type, since it can be attenuated and even completely overcome by increasing the activator concentration.