34046

Lysozyme from chicken egg white

VETRANAL^®, analytical standard

• Synonym(s): Mucopeptide N-acetylmuramoylhydrolase, Muramidase
• CAS Number: 12650-88-3
• Enzyme Commission number: 3.2.1.17 (BRENDA, IUBMB)
• EC Number: 232-954-0
• MDL number: MFCD00131557
• UNSPSC Code: 41116107
• NACRES: NA.24

Properties

• grade: analytical standard
• Quality Level: 100
• product line: VETRANAL^®
• specific activity: 8000-120000 U/mg
• shelf life: limited shelf life, expiry date on the label
• mol wt: single-chain 14.3 kDa; M_r ~14000
• analyte chemical class(es): amino acids, peptides, proteins
• technique(s): HPLC: suitable
• application(s): food and beverages
• format: neat

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

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)].[3]
• Food samples using high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA).[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).

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.

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

Safety Information

• pictograms: GHS08
• signalword: Danger
• hcodes: H334
• pcodes: P261 - P284 - P501
• Hazard Classifications: Resp. Sens. 1
• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: Eyeshields, Gloves, type N95 (US)