Lysozyme C (Gallus gallus) (HEWL)

Hen egg white lysozyme (HEWL), also known as Lysozyme C, is a 129-amino acid enzyme derived from the egg white of Gallus gallus. It is one of the most extensively studied proteins in history, serving as a cornerstone model for understanding enzyme catalysis, protein folding, and X-ray crystallography [1, 3]. Biologically, it functions as part of the innate immune system by hydrolyzing the beta-1,4-glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine in bacterial peptidoglycan, leading to cell lysis [1, 2]. The specific mention of Aspartic acid (Asp), Glutamic acid (Glu), and Asparagine (Asn) side chains refers to the critical residues in the active site, particularly Glu35 and Asp52, which facilitate the acid-base catalysis mechanism, and Asn residues involved in substrate orientation [3]. While HEWL is not a therapeutic target for drug development in humans, it is a significant clinical entity as a major food allergen (Gal d 4) capable of triggering severe IgE-mediated hypersensitivity reactions [4]. In research, it is frequently used as a model target for testing fragment-based drug discovery methods and small molecule binding assays [3].

Other names

Hen egg-white lysozymeMuramidaseAllergen Gal d 41,4-beta-N-acetylmuramidase C

Hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan via acid-base catalysis involving Glu35 and Asp52