Some properties of egg-white lysozyme

Abstract

Lysozyme prepared by Roberts'' method appeared to be homogeneous in the ultracentrifuge and to have a molecular wt. of about 18,000. A colorimetric estimation of certain amino-acids and a Van Slyke estimation of amino-N were carried out, and arginine was isolated in the form of its flavianate. The solubility of the material subsequently showed that it was not completely homogeneous but that a fraction could be separated of lower activity and much lower solubility than the rest. Electrometric titration of the soluble lysozyme showed it to be a basic protein with an acid-binding capacity not far from 23 groups per molecule. At pH 11.5 the base-binding in water, at 25[degree], corresponded to about 15 groups per molecule. The acid- and base-binding capacities of the insoluble fraction were somewhat larger.