Non disponible en dehors du Royaume-Uni et de l'Irlande

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).