Purification and crystallization of avidin

Abstract

An improved purification, including crystallization, of avidin from hen's-egg white is described. The product bound 15.1mug of biotin/mg, corresponding to an equivalent weight of 16200. The amino acid composition showed an integral number of amino acid residues per 16200g, which suggested that each molecule of avidin (mol. wt. approx. 66000) contained four identical subunits.