Enzymatic activity of avian egg-white lysozymes.

The experimental time-courses of eight avian lysozymes, seven hen-type lysozymes and one goose-type lysozyme, were measured with a substrate of chitopentaose (GlcNAc)5 at pH 5.0 and 50 degrees C. Chitooligosaccharides in the reaction mixture were analyzed by high-performance gel-filtration. From the experimental time-courses, the overall reaction rates represented by the disappearance of the initial substrate and the values of reaction parameters were estimated by computer analysis. With taking hen lysozyme as the reference, the values of reaction parameters estimated were correlated to the replaced amino acid residue in the binding site of the lysozyme, and the roles of some amino acid residues in the binding site were discussed.