Peptidoglycan layer of bacterial cell walls (specifically hydrolyzes the β(1-4) glycosidic linkage between N-acetylmuramic acid and N-acetylglucosamine). [1]
Lysozyme from chicken egg white binds to elastic fibers in the extracellular matrix. It also binds to hyaluronan (HA) and may interact with other anionic matrix components.[3]

Lysozyme is a common enzyme. Eggs are the highest source of lysozyme, accounting for around 3.4% of protein. Lysozyme is a natural antibiotic that changes the β(1-4) sugar series relationship between the presence of N-acetylmuramic acid and N-acetylglucosamine in the peptidase layer of the bacterial cell wall, resulting to duct cells. The bactericidal activity of lysozyme largely inhibits Gram-positive fungi, including carotenoids, such as Listeria monocytogenes and Clostridium, as well as some spoilage organisms, including thermophilic spore-forming bacteria Gram-negative bacteria. Its complex cell wall construction promotes resistance to the action of lysozyme [1]. Lysozyme (1 mg/mL) can impair the ability of hyaluronic acid (HA) to prevent antibiotic damage to elastic fibers [3].

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The lytic (bacteriolytic) activity of purified Lysozyme from chicken egg white and unpurified egg white (containing lysozyme) was tested under varying conditions of temperature (5°C and 22°C), pH (4.5, 6.5, 8.0, 9.5), and CO₂ treatment (with and without). The activity was measured against Micrococcus lysodeikticus.
The highest lytic activity for both purified and unpurified lysozyme was observed at pH 6.5 and 22°C without CO₂ addition.
At pH 4.5, the addition of CO₂ increased the lytic activity of purified lysozyme by more than 50% at both 5°C and 22°C. For unpurified egg white, CO₂ addition increased activity by 25% at 5°C and 48% at 22°C.
At pH 6.5, CO₂ addition caused a minimal decrease in activity (less than 10% for purified, ~20% for egg white) at 22°C, but no decrease was observed at 5°C.
At pH 8.0, CO₂ treatment (either as bubbled CO₂ gas in bicine buffer or as NaHCO₃ solution) significantly increased the lytic activity of purified lysozyme. The increase was more pronounced with NaHCO₃ (bicarbonate) than with CO₂ gas, showing a 102% higher activity at 5°C and 25% higher at 22°C compared to the gas treatment.
At pH 9.5, the addition of CO₂ gas completely eliminated (reduced to zero) the lytic activity of both purified lysozyme and egg white at both temperatures, whereas activity was present in the absence of CO₂.
Overall, lytic activity was consistently higher at 22°C compared to 5°C across most conditions. [1]
The study describes the adsorption capacity and selectivity of synthesized magnetic molecularly imprinted nanoparticles (Fe₃O₄@SiO₂@MIPs) for Lysozyme from chicken egg white.
The adsorption isotherm followed a Langmuir model, with a calculated saturated adsorption capacity (Q_m) of the MIPs for lysozyme of 0.11 mg per mg of nanoparticles.
In selectivity experiments using a protein concentration of 0.5 mg mL⁻¹, the MIPs showed the highest adsorption capacity for lysozyme compared to control proteins cytochrome c, ribonuclease A, and bovine serum albumin (BSA). The adsorption capacity for cytochrome c (similar size and pI to lysozyme) was higher than for ribonuclease A (similar size, different pI). MIPs and non-imprinted nanoparticles (NIPs) showed similar low adsorption for BSA (different size and pI).
The adsorption kinetics were slower for MIPs (reaching equilibrium in about 100 min) compared to NIPs (about 60 min), attributed to the time needed for the template protein to fit into the specific imprinted cavities.
The adsorption capacity of the MIPs for lysozyme was influenced by salt (NaCl) concentration, decreasing as NaCl concentration increased from 0 to 100 mmol L⁻¹. The maximum adsorption capacity and imprinting factor (I = 8.4) were observed at 0.02 mol L⁻¹ NaCl.
The MIPs nanoparticles were used to preconcentrate and purify lysozyme from spiked human serum samples, followed by detection via a chemiluminescence (CL) assay. The CL response was linear for lysozyme concentrations from 5 to 2000 ng mL⁻¹. Spiked recoveries in serum samples ranged from 92.5% to 113.7%, with relative standard deviations (RSD) lower than 11.8%. [2]
Treatment of a biosynthetically radiolabeled extracellular matrix (mainly composed of elastic fibers) with lysozyme from chicken egg white (1 mg/ml) did not significantly increase the release of radioactivity (elastolysis) upon subsequent exposure to 1 µg/ml or 100 ng/ml porcine pancreatic elastase, compared to untreated controls. This indicates that lysozyme itself does not degrade elastic fibers and does not significantly enhance their susceptibility to elastase directly.
However, pretreatment of the radiolabeled matrix with lysozyme from chicken egg white (1 mg/ml) prior to incubation with HA (1 mg/ml) significantly impaired the protective effect of HA against elastase-induced elastolysis. When matrix was treated with lysozyme then HA, followed by 1 µg/ml elastase, radioactivity release was 3106 cpm vs. 2325 cpm for HA treatment alone (P<0.05). With 100 ng/ml elastase, release was 1055 cpm vs. 596 cpm for HA alone (P<0.05). When the order was reversed (HA first, then lysozyme), the increase in elastolysis was not statistically significant.
Immunofluorescence studies confirmed that lysozyme from chicken egg white binds to the elastic fibers within the matrix preparation.
Treatment of the radiolabeled matrix with lysozyme from chicken egg white alone at 1 mg/ml or 100 µg/ml for 3 hours produced no significant release of radioactivity (<50 cpm), demonstrating the protein itself lacks elastolytic activity. [3]

Airway dilatation in Syrian hamsters was significantly increased when they were exposed to nebulized lysozyme (20 mg in 20 ml of water; 50 min) prior to the administration of elastase [3].

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Syrian hamsters exposed to aerosolized lysozyme from chicken egg white (20 mg in 20 ml water, 50 min exposure) prior to intratracheal instillation of porcine pancreatic elastase (40 units) showed significantly enhanced airspace enlargement (emphysema) compared to controls exposed to aerosolized water. The mean linear intercept (measure of airspace size) was 123 µm in lysozyme-treated animals versus 75 µm in controls (P < 0.0001). [3]

The lytic activity of Lysozyme from chicken egg white was assessed using a standard microbial assay based on the decrease in turbidity of a Micrococcus lysodeikticus suspension.
A 0.015% (w/v) suspension of lyophilized Micrococcus lysodeikticus was prepared in buffers of specific pH (4.5, 6.5, 8.0, 9.5). A 0.001% (w/v) solution of purified lysozyme was prepared in the same buffers. For testing, a cuvette containing a 7:1 ratio of the Micrococcus suspension to the lysozyme solution (total volume 3.0 mL) was prepared. The decrease in absorbance (turbidity) at 450 nm was measured using a spectrophotometer at 30-second intervals for 9 minutes. The slope of the linear decrease in turbidity was calculated and represents the lytic activity. All activities were normalized to the maximum activity observed (pH 6.5, 22°C, without CO₂).
For unpurified lysozyme (egg white), fresh egg white was added to the buffers to achieve an estimated final lysozyme concentration of 0.001%, based on the known average lysozyme content (3.4%) in egg white. The assay procedure was otherwise identical.
The influence of CO₂ was tested by saturating the buffer solutions with CO₂ gas prior to adding the enzyme/substrate. Carbonation was achieved by bubbling CO₂ gas at 9 mL/min for approximately 150 seconds for pH 4.5, 6.5, and 8.0, and for 12 seconds for pH 9.5. An alternative CO₂ source at pH 8.0 was a 0.504% NaHCO₃ (sodium bicarbonate) solution.
Ionic conductivity of all buffer solutions was measured and adjusted to be similar to that of liquid egg white (average 8.11 mS) to control for the known effect of ionic strength on lysozyme activity.
CO₂ content in the carbonated buffers was quantified using an acidification and titration method to ensure consistent saturation levels across experiments. [1]
A radiolabeled, cell-free extracellular matrix preparation, biosynthetically labeled with 14C-lysine and rich in elastic fibers, was used as a substrate to assess elastolysis. Matrix squares were incubated with test solutions. To evaluate the effect on elastase-mediated injury, matrices were first treated with lysozyme from chicken egg white (1 mg/ml in PBS) or control buffer for 30 min at room temperature. After drying, they were incubated with porcine pancreatic elastase (1.0 µg/ml or 100 ng/ml in Tris buffer, pH 8.0) for 3 hours at 37°C. The released radioactivity in the supernatant was measured using a liquid scintillation spectrometer, and net counts per minute (cpm) were calculated after subtracting background. [3]

Immunofluorescence was used to detect the binding of lysozyme from chicken egg white to the matrix and to identify elastic fibers. Matrix samples grown on coverslips were incubated with lysozyme (1 mg/ml) or buffer. After washing, samples were fixed and incubated with a primary rabbit anti-lysozyme antiserum, followed by a fluorescein-labeled secondary goat anti-rabbit IgG antibody. Samples were examined by fluorescence microscopy.
To identify elastic fibers in the matrix, a separate immunofluorescence protocol was used. Matrix samples were fixed and incubated with a primary goat anti-rat lung α-elastin antibody, followed by a fluorescein-labeled secondary rabbit anti-goat IgG antibody, and examined. [3]

Syrian hamsters (~100 g) were placed in a chamber and exposed to an aerosol generated from a solution of lysozyme from chicken egg white (20 mg dissolved in 20 ml water) for 50 minutes using a nebulizer connected to a compressed air source. Control animals were exposed to aerosolized water (20 ml) alone. Thirty minutes after aerosol exposure, animals were anesthetized and administered porcine pancreatic elastase (40 units in 0.2 ml normal saline) via intratracheal instillation using a needle and syringe. Animals were sacrificed one week later. Lungs were fixed in situ by tracheal instillation of 10% neutral-buffered formalin at a pressure of 20 cm H2O. After further fixation, lung tissues were processed, sectioned, stained with hematoxylin and eosin, and mean linear intercepts were measured morphometrically to quantify airspace enlargement. [3]

Immunofluorescence studies in hamsters showed that aerosolized egg white lysozyme could be detected in the lung interstitium 30 minutes after inhalation and could still be detected in alveolar macrophages 24 hours after exposure. [3]

Syrian hamsters exposed alone to egg white lysozyme aerosol (20 mg dissolved in 20 mL of water for 50 minutes) showed no significant inflammatory changes in their lungs 24 hours later. [3]

[1]. Influence of carbon dioxide on the activity of chicken egg white lysozyme. Poult Sci. 2011 Apr;90(4):889-95.

[2]. Magnetic molecularly imprinted nanoparticles for recognition of lysozyme. Biosens Bioelectron. 2010 Oct 15;26(2):301-6.

[3]. The effect of lysozyme on elastase-mediated injury. Exp Biol Med (Maywood). 2002 Feb;227(2):108-13.

Lysozyme is a soluble protein immunogen used as a model antigen in laboratory studies of antibody-antigen binding and B-cell and T-cell responses. (NCI04) Lysozyme is an alkaline enzyme found in saliva, tears, egg white, and many animal body fluids, possessing antibacterial activity. This enzyme catalyzes the hydrolysis of 1,4-β-glycosidic bonds between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan, and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17. Egg white lysozyme is a natural antibacterial enzyme, comprising approximately 3.4% of egg white protein. Lysozyme primarily exerts its bactericidal effect by hydrolyzing key bonds in the peptidoglycan cell wall of Gram-positive bacteria (such as Listeria monocytogenes and certain Clostridium species), leading to cell lysis. Gram-negative bacteria, due to the presence of their outer membrane, generally exhibit stronger resistance. The isoelectric point of the enzyme is pH 10.7, and the optimal activity pH is between 5.3 and 6.4. This study explores how environmental factors (pH, temperature) and the presence of carbon dioxide (or its dissociated form, such as bicarbonate) affect its enzyme activity, which is of great significance for egg storage and food safety. The mechanism by which carbon dioxide enhances enzyme activity at a specific pH may involve interaction with amino acid residues, thereby reducing hydrophobic interactions and promoting the formation of a more active conformation of the enzyme. [1]
Egg white lysozyme is mainly described in the literature as a template molecule for constructing molecularly imprinted polymers (MIPs). Lysozyme (N-acetylmuramidoside hydrolase) is a self-defense enzyme found in the serum, mucus and organs of vertebrates. Its applications include: as an important diagnostic indicator for diseases such as kidney disease and leukemia; as a cell destroyer in ophthalmic preparations; as a food additive in dairy products; and as a drug for treating ulcers and infections. In addition, animal experiments and in vitro cell chemotherapy studies have shown that lysozyme has potential use in the treatment of HIV infection. This highlights the importance of isolating and purifying lysozyme from complex matrices. This study proposes a novel method for isolating lysozyme using magnetic molecularly imprinted polymer (MIP) nanoparticles. [2] This study suggests that egg white lysozyme, which is present in elevated levels in human emphysema and can bind to elastic fibers, may play a role in the pathogenesis of the disease. Lysozyme does not directly degrade elastic fibers, nor does it significantly increase their direct sensitivity to elastase. However, its primary role appears to be to disrupt the protective binding between hyaluronic acid (HA) and elastic fibers, thereby indirectly promoting elastase-mediated damage and alveolar expansion in an elastase-induced emphysema model. The cationic nature of lysozyme is related to its binding to anionic matrix components such as HA. [3]

C125H1961N40O36S2

2899.27014

2235.244

12650-88-3

Lysozyme chloride;9066-59-5

91976556

White to off-white solid powder

-7.4

38

29

75

159

5020

0

S(C([H])([H])[H])C([H])([H])C([H])([H])[C@@]([H])(C(N([H])[C@]([H])(C(N([H])[C@]([H])(C(N([H])[C@]([H])(C(N([H])C([H])([H])C(N([H])[C@]([H])(C(N([H])[C@]([H])(C(N([H])[C@@]([H])(C([H])([H])C(N([H])[H])=O)C(N([H])[C@]([H])(C(N([H])[C@]([H])(C(N([H])C([H])([H])C(N([H])[C@]([H])(C(N([H])[C@@]([H])(C([H])([H])O[H])C(N([H])[C@]([H])(C(N([H])C([H])([H])C(N([H])[C@]([H])(C(=O)O[H])C([H])([H])C(N([H])[H])=O)=O)=O)C([H])([H])C([H])(C([H])([H])[H])C([H])([H])[H])=O)=O)C([H])([H])C1C([H])=C([H])C(=C([H])C=1[H])O[H])=O)=O)C([H])([H])C([H])([H])C([H])([H])N([H])/C(=N/[H])/N([H])[H])=O)C([H])([H])C1C([H])=C([H])C(=C([H])C=1[H])O[H])=O)=O)C([H])([H])C(=O)O[H])=O)C([H])([H])C([H])(C([H])([H])[H])C([H])([H])[H])=O)=O)C([H])([H])C1=C([H])N=C([H])N1[H])=O)C([H])([H])C([H])([H])C([H])([H])N([H])/C(=N/[H])/N([H])[H])=O)C([H])([H])C([H])([H])C([H])([H])C([H])([H])N([H])[H])=O)N([H])C([C@]([H])(C([H])([H])[H])N([H])C([C@]([H])(C([H])([H])[H])N([H])C([C@]([H])(C([H])([H])[H])N([H])C([C@]([H])(C([H])([H])C([H])(C([H])([H])[H])C([H])([H])[H])N([H])C([C@]([H])(C([H])([H])C([H])([H])C(=O)O[H])N([H])C([C@]([H])(C([H])([H])S[H])N([H])C([C@]([H])(C([H])([H])C([H])([H])C([H])([H])N([H])/C(=N/[H])/N([H])[H])N([H])C(C([H])([H])N([H])C([C@]([H])(C([H])([H])C1C([H])=C([H])C([H])=C([H])C=1[H])N([H])C([C@]([H])(C([H])(C([H])([H])[H])C([H])([H])[H])N([H])[H])=O)=O)=O)=O)=O)=O)=O)=O)=O)=O

ZJCXKXFAOCLSRV-UHFFFAOYSA-N

InChI=1S/C99H159N37O23/c1-11-50(8)77(132-72(139)46-120-81(145)63(32-33-70(101)137)124-88(152)69-31-21-39-136(69)93(157)68(43-73(140)141)131-84(148)62(29-19-37-116-98(109)110)125-90(154)75(48(4)5)135-91(155)76(49(6)7)133-80(144)57(100)24-16-34-113-95(103)104)92(156)126-60(27-17-35-114-96(105)106)82(146)121-51(9)78(142)129-66(41-54-45-119-59-26-15-13-23-56(54)59)87(151)134-74(47(2)3)89(153)122-52(10)79(143)128-65(40-53-44-118-58-25-14-12-22-55(53)58)85(149)123-61(28-18-36-115-97(107)108)83(147)130-67(42-71(102)138)86(150)127-64(94(158)159)30-20-38-117-99(111)112/h12-15,22-23,25-26,44-45,47-52,57,60-69,74-77,118-119H,11,16-21,24,27-43,46,100H2,1-10H3,(H2,101,137)(H2,102,138)(H,120,145)(H,121,146)(H,122,153)(H,123,149)(H,124,152)(H,125,154)(H,126,156)(H,127,150)(H,128,143)(H,129,142)(H,130,147)(H,131,148)(H,132,139)(H,133,144)(H,134,151)(H,135,155)(H,140,141)(H,158,159)(H4,103,104,113)(H4,105,106,114)(H4,107,108,115)(H4,109,110,116)(H4,111,112,117)

2-[[4-amino-2-[[2-[[2-[2-[[2-[[2-[2-[[2-[[2-[[2-[[5-amino-2-[[1-[2-[[2-[[2-[[2-[(2-amino-5-carbamimidamidopentanoyl)amino]-3-methylbutanoyl]amino]-3-methylbutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-3-carboxypropanoyl]pyrrolidine-2-carbonyl]amino]-5-oxopentanoyl]amino]acetyl]amino]-3-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoylamino]-3-(1H-indol-3-yl)propanoyl]amino]-3-methylbutanoyl]amino]propanoylamino]-3-(1H-indol-3-yl)propanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-oxobutanoyl]amino]-5-carbamimidamidopentanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~10 mg/mL

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)