Application

Lysozyme from chicken egg white has been used for the extraction of genomic DNA from bacterial cells. It has been used as an external standard for MALDI-TOF (matrix assisted laser desorption ionization-time of flight) mass analysis.

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

Biochem/physiol Actions

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).

Other Notes

View more information on enzymes for complex carbohydrate analysis at www.sigma-aldrich.com/enzymeexplorer

Packaging

1, 5, 10, 25, 100 g in poly bottle

Unit Definition

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).