Lysozyme Type VI from Chicken Eggwhite, 5g

Lysozyme (muramidase) hydrolyzes preferentially the b-1,4 glucosidic linkages between N-acetylmuramic acid and N-acetylglucosamine which occur in the mucopeptide cell wall structure of certain microorganisms, such as Micrococcus lysodeikticus. Lysozyme has been used for lysing E. coli and Streptomycetes for extraction purposes such as extracting group specific antigen. It would appear that lysozyme may act as a germinative agent of bacterial spores. In humans, lysozyme may be the mediator in the anti-tumor function of macrophages which, it has been shown, secrete the enzyme. There is evidence that cartilage lysozyme has a role in cartilage calcification. 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). One unit will produce a decrease in A450 of 0.001 per minute at pH 6.24 and 25°C using Micrococcus lysodeikticus as substrate.