Abstract
With the purified perparation of the tannase of Aspergillus fiavus, some physicochemical properties were investigated. The purified enzyme was homogeneous when examined in the ultracentrifuge and electrophoresis. The molecular weight determined by the sedimen. tation-diffusion method, was found to be 194, 000. The Archibald approach-to-equilibrium method gave a molecular weight of 192, 000. The enzyme was a glycoprotein containing 25.4% hexose and showed an isoelectric point in the vicinity of pH 4.0.
The nitrogen content of the enzyme was determined to be 12.9% by the micro-Kjeldahl method. The amino terminal amino acids were composed of approximately l mole each of alanine and arginine per mole of enzyme by the DNP-method. Evidence is presented to show that the enzyme undergoes dissociation into inactive subunits of equal size by the treatment with guanidine hydrochloride.
