Lysozyme

Lysozyme (Muramidase) is a conserved antimicrobial protein. Lysozyme exerts its bactericidal effect by hydrolyzing bacterial cell wall peptidoglycan (PG). Lysozyme plays an important role in limiting bacterial growth on mucosal surfaces and other sites, not only controlling potential pathogens but also limiting overgrowth of microbiota to prevent dysbiosis. Extracellular lysozyme can also degrade polymeric PG into soluble fragments, activate NOD receptors in mucosal epithelial cells, and lead to the secretion of chemokines and activating factors by neutrophils and macrophages[1][2].

[1]Feingold DS, et al. Locus of the action of serum and the role of lysozyme in the serum bactericidal reaction. J Bacteriol. 1968 Dec;96(6):2118-26.|[2]Ragland S A, et al. From bacterial killing to immune modulation: Recent insights into the functions of lysozyme[J]. PLoS pathogens, 2017, 13(9): e1006512.|[3]Markart P, et al. Mouse lysozyme M is important in pulmonary host defense against Klebsiella pneumoniae infection[J]. American journal of respiratory and critical care medicine, 2004, 169(4): 454-458.|[4]Lee M, et al. Hen egg lysozyme attenuates inflammation and modulates local gene expression in a porcine model of dextran sodium sulfate (DSS)-induced colitis[J]. Journal of agricultural and food chemistry, 2009, 57(6): 2233-2240.