Description

• Application: Lysozyme from chicken egg white has been used:as a standard in small-angle neutron scattering experiments [1] and infrared absorbance spectroscopy[2]as a constituent of cell lysis buffer[3]in protein crystallization experiments[4]
• 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).
• Unit Definition: 1 U corresponds to the amount of enzyme which decreases the absorbance at 450 nm by 0.001 per minute at pH 7.0 and 25°C (Micrococcus luteus, ATCC 4698, as substrate)
• Other Notes: Suitable for the hydrolysis of bacterial cell walls, mucopolysaccharides, mucopolypeptides or chitin; degradability of L. lactis subsp. cremoris H2 cell walls[5]; Review[6][7][8]