Lysozyme from chicken egg white

Application
Enzyme breaks down the cell walls of bacteria; used to prepare spheroplasts.
Lysozyme from chicken egg white may be used as an analytical reference standard for the determination of the analyte in:
Hard and pasta filata cheeses using reversed-phase high performance liquid chromatography with diode array and fluorimetric detection [(RP-HPLC-DAD) and (RP-HPLC-FLD)].[1] Food samples using high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA).[2]

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).
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.
General description
Lysozyme from chicken egg white, is a protein that can show broad spectrum of antibacterial activity against gram positive and gram negative bacteria.[3][4] Its antimicrobial activity can be enhanced by pretreatment of the target microbial cells with chelating agents like ethylenediaminetetraacetic acid (EDTA).[4] Other Notes
1 unit corresponds to the amount of enzyme which decreases the absorbance at 450 nm by 0.001 per minute at pH 7.0 and 25 deg C.
Legal Information
VETRANAL is a registered trademark of Merck KGaA, Darmstadt, Germany