Lysozymes are enzymes that damage bacterial cell walls by
catalyzing 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
is abundant in a number of secretions, such as tears, saliva, human
milk, and mucus. It is also present in cytoplasmic granules of the
macrophages and the polymorphonuclear neutrophils (PMNs).