A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 126.96.36.199.
Muramidase is also known as Lysozyme is an antimicrobial enzyme produced by animals that form part of the innate immune system. Muramidase is a glycoside hydrolase that catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan, which is the major component of the gram-positive bacterial cell wall. This hydrolysis in turn compromises the integrity of bacterial cell walls causing lysis of the bacteria.
Muramidase is abundant in secretions including tears, saliva, human milk, and mucus. Large amounts of muramidase can be found in egg white.
Hen egg-white lysozyme is thermally stable, with a melting point reaching up to 72 °C at pH 5.0. Hen egg-white lysozyme maintains its activity in a large range of pH (6-9).