溶菌酶 Lysozyme 0663

溶菌酶

Lysozyme, Egg white
溶菌酶

说明： 生化研究；溶菌酶可用于水解革兰氏阳性菌和革兰氏阴性
菌的细胞壁。
别名： 胞壁质酶；Globulin G1；Muramidase
CAS＃：12650-88-3
外观：白色冻干粉或结晶
R：42/43 S：36/37/39
储存条件：-20℃






溶菌酶

溶菌酶（lysozyme）又称胞壁质酶（muramidase）或N-乙酰胞壁质聚糖水解酶（N-acetylmuramide glycanohydrlase），是一种能水解致病菌中黏多糖的碱性酶。主要通过破坏细胞壁中的N-乙酰胞壁酸和N-乙酰氨基葡糖之间的β-1,4糖苷键，使细胞壁不溶性黏多糖分解成可溶性糖肽，导致细胞壁破裂内容物逸出而使细菌溶解。溶菌酶还可与带负电荷的病毒蛋白直接结合，与DNA、RNA、脱辅基蛋白形成复盐，使病毒失活。因此，该酶具有抗菌、消炎、抗病毒等作用。


白色或微白色冻干粉，溶于水，不溶于和bing酮，pI为11.0-11.35，最适pH值6.5。
稳定性：酸性介质中可稳定存在，碱性介质中易失活；96℃， pH值为3条件下，15min后活力保持87%。
抑制剂：有碘、咪唑和吲哚衍生物、表面活性剂(十二烷基硫酸钠、醇类和碳链不少于12的脂肪酸)。1%水溶液在281.5nm处的吸光系数为26.4。通过水解细菌细胞壁的肽聚糖来溶菌。
酶反应：Micrococcus luteus或Micrococcus lysodeikticus菌悬浮液═溶菌并澄清。
用途：用于生化研究，临床上用于急慢性咽喉炎、扁平苔癣、扁平疣等疾病的治疗。

LYSOZYME, EGG WHITE
Grade: ULTRA PURE GRADE
Appearance: White crystallized powder
Storage ：Store frozen. Keep dry. Warm to room temperature before opening.
Product Description
Lysozyme is a single chain polypeptide of 129 amino acids cross-linked with four disulfide
bridges. Ithydrolyzes β(1→4) linkages between N-acetyl-muraminic acid and N-acetyl-D-
glucosamine residues in peptidoglycan and between N-acetyl-D- glucosamine residues in
chitodextrin.
The enzyme is often used for lysing bacterial cells by hydrolyzing the peptidoglycan present in
the cell walls. 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 more easily in the presence of EDTA that chelates metal ions in the outer bacterial
membrane.
Optimal pH:
The activity of lysozyme is a function of both pH and ionic strength. The enzyme is active over a
broad pH range (6.0–9.0). At pH 6.2, maximal activity is observed over a wider range of ionic
strengths (0.02–0.100 M) than at pH 9.2 (0.01–0.06 M).
Inhibitors:
Lysozyme is inhibited by indole derivatives, which bind to and distort the active site, and
imidazole, which induces the formation of a charge-transfer complex.
It is also inhibited by surface-active agents such as sodium dodecyl sulfate, sodium dodecanate,
and dodecyl alcohol. Other compounds of these types with carbon chains of 12 or more carbons in
length will also inhibit lysozyme.
Substrates:
The natural substrate for lysozyme is the peptidoglycan layer of bacterial cell walls. However, a
variety of low molecular mass substrates including murein degradation products as well as
synthetic compounds have been used for various photometric, isotopic, and immunological
lysozyme assays.
Precautions and Disclaimer
This product is for R&D use only, not for drug, household, or other uses.
Preparation Instructions
For E. coli cell lysis, use a freshly prepared lysozyme solution (10 mg/ml) in 10 mM Tris-HCl, pH
8.0.
The product is also soluble in water (10 mg/ml) yielding a clear to slightly hazy colorless solution.
Aqueous solutions should retain activity for at least one month when stored between 2–8 °C.
Storage/Stability
The product, as supplied, should be stored at –20 °C. When stored at –20 °C, the enzyme retains
activity for at least 4 years.
Solutions (pH 4–5) remain active for several weeks if refrigerated.
Procedure
The following procedure is for the lysis of E. coli. It may be used as a guideline for other species.
The optimal pH for E. colicell lysis is 8.0±0.1.
1. Incubate E. coli strain bearing the pBR322 plasmid overnight with 25 μg/ml tetracycline and 25
μg/ml ampicillin.
2. Centrifuge 1–2 ml samples of the overnight culture.
3. Resuspend the pellets in 350 μl of STET buffer (10mM Tris-HCl, pH 8.0, with 0.1 M NaCl, 1
mM EDTA, and 5% [w/v] TRITON X-100).
4. Add 25 μl of a freshly prepared lysozyme solution (10 mg/ml in 10 mM Tris-HCl, pH 8.0).
5. Mix by vortexing for 3 seconds.
6. Incubate the lysis mixture for 30 minutes at 37 °C
7. After incubation, place the tube containing the lysis mixture in a boiling water bath for exactly
40 seconds.
8. Centrifuge the lysis mixture at 14,000 g.
9. Remove the pellet (cell debris) from the tube using a sterile toothpick.
10.Plasmid DNA from the supernatant may then be purified and analyzed