Lysozyme from chicken egg white

Enzyme breaks down the cell walls of bacteria; used to prepare spheroplasts.

Lysozyme hydrolyzes the β-1,4 linkages between N-acetylmuramic acid and N-acetylglucosamine, a polysaccharide backbone of peptidoglycans in the cell wall structure of many microorganisms. This is particularly useful for lysing Gram-positive and Gram-negative bacteria for subsequent nucleic acid extraction.

Lysozyme hydrolyzes β(1→4) linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. Gram-positive cells are quite susceptible to this hydrolysis as their cell walls have a high proportion of peptidoglycan. Gram-negative bacteria are less susceptible due to the presence of an outer membrane and a lower proportion of peptidoglycan. However, these cells may be hydrolyzed in the presence of EDTA that chelates metal ions in the outer bacterial membrane.

The enzyme is active over a broad pH range (6.0 to 9.0). At pH 6.2, maximal activity is observed over a wider range of ionic strengths (0.02 to 0.100 M) than at pH 9.2 (0.01 to 0.06 M).

One unit will produce a ΔA₄₅₀ of 0.001 per min at pH 6.24 at 25°C, using a suspension of Micrococcus lysodeikticus as substrate, in a 2.6 mL reaction mixture (1 cm light path).

Lyophilized powder, essentially salt-free

3× crystallized