Description

• 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.[1][2] Its antimicrobial activity can be enhanced by pretreatment of the target microbial cells with chelating agents like ethylenediaminetetraacetic acid (EDTA).[2]
• Application: 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)].[5]Food samples using high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA).[6]
• 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 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