Lysozymes have primarily a bacteriolytic function; those in tissues and body fluids are associated with the monocyte-macrophage system and enhance the activity of immunoagents. Hydrolysis of (1->4)-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrins. Lysozyme C is capable of both hydrolysis and transglycosylation; it shows also a slight esterase activity. It acts rapidly on both peptide-substituted and unsubstituted peptidoglycan, and slowly on chitin oligosaccharides. The sequence of the DL-2 variant of lysozyme C from Pekin duck is shown. As only one lysozyme, or any combination of 2 lysozymes, but never all 3, occurred in one egg, the existence of 3 alleles at one locus has been suggested. The amino acid compositions of DL-1, DL-2, and DL-3 are identical with those of lysozymes A, B, and C, respectively. DL-1 and DL-2 are electrophoretically and immunologically indistinguishable from lysozymes A and B, respectively. Belongs to the glycosyl hydrolase 22 family.