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| 1mg |
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| Other Sizes |
| Targets |
Chicken ovomucoid is a competitive and highly specific inhibitor of the pancreatic serine protease, trypsin. It accomplishes this by binding to the active site of trypsin with high affinity. The third domain of the ovomucoid protein is primarily responsible for this strong inhibitory activity, which involves the formation of a stable, stoichiometric 1:1 complex between the inhibitor and the enzyme, effectively blocking its catalytic activity. Because its mechanism is competitive, it directly binds to the same site as the trypsin's natural substrate. Its role as a potent allergen is mediated by its recognition and cross-linking by specific Immunoglobulin E (IgE) antibodies on the surface of mast cells and basophils, triggering an allergic cascade.
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| ln Vitro |
In vitro, the primary activity of chicken ovomucoid is its ability to inhibit the enzymatic activity of trypsin. In a trypsin assay, ovomucoid will block the cleavage of a chromogenic substrate, such as Nalpha-Benzoyl-DL-arginine 4-nitroanilide (BAPNA). The IC₅0 for trypsin inhibition is in the nanomolar range (approximately 1-10 nM). In cell-based assays, ovomucoid is used to stimulate immune cells (e.g., mast cells or basophils) from allergic donors. It triggers these cells to release histamine and other mediators (e.g., beta-hexosaminidase), with an EC₅0 typically in the range of 10-100 ng/mL. It is not cytotoxic at these concentrations, and it has no activity on other proteases like chymotrypsin or thrombin.
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| ln Vivo |
As a purified food allergen and research reagent, chicken ovomucoid does not have a therapeutic in vivo activity. When introduced into a sensitized organism (e.g., in a mouse model of egg allergy), it potently induces an allergic response. In an active systemic anaphylaxis model, administration of ovomucoid to sensitized mice leads to a drop in body temperature, an increase in serum histamine and mast cell protease-1 (mMCP-1), and other signs of severe systemic anaphylaxis. In a passive cutaneous anaphylaxis (PCA) model, intradermal injection of ovomucoid followed by intravenous administration of an anti-ovomucoid IgE antibody leads to localized vascular leakage (measurable by Evans blue dye extravasation). These activities are purely pathological, not therapeutic.
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| Enzyme Assay |
General in vitro trypsin inhibition assay: A 96-well plate is used. Recombinant trypsin (10 ng/well) is pre-incubated with increasing concentrations of chicken ovomucoid (0.1-100 nM) for 10 minutes at 37degC. The chromogenic substrate Nalpha-Benzoyl-DL-arginine 4-nitroanilide (BAPNA, 100 uM) is then added. The reaction is monitored by measuring the absorbance at 405 nm for 30 minutes. The half-maximal inhibitory concentration (IC₅0) is calculated from the inhibition curve. Ovomucoid will inhibit trypsin activity in a dose-dependent manner, with an IC₅0 in the low nanomolar range (e.g., 1-5 nM).
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| Cell Assay |
General in vitro human basophil activation assay (Ige-mediated response): Peripheral blood mononuclear cells (PBMCs) from an egg-allergic donor are isolated and resuspended. Cells are incubated with increasing concentrations of chicken ovomucoid (0.1-1000 ng/mL) for 1 hour at 37degC. Basophil activation is assessed by flow cytometry using CD63 and CD203c surface markers. The EC₅0 for basophil activation is typically in the range of 10-100 ng/mL, depending on the donor's sensitization level. A positive control is anti-human IgE antibody. This assay is the standard method for in vitro diagnosis of IgE-mediated food allergies.
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| Animal Protocol |
General in vivo animal protocol for passive cutaneous anaphylaxis (PCA) model: Female BALB/c mice are injected intradermally with 20 uL of anti-ovomucoid IgE antibody (10 ug/mL) in separate sites on the back. 24 hours later, a mixture of chicken ovomucoid (500 ug) and 1% Evans blue dye in saline is injected intravenously. After 30 minutes, the mice are euthanized. The skin is removed, and the extravasated Evans blue dye is extracted from the injection sites with formamide. The absorbance of the extract is measured at 620 nm to quantify dye leakage. This model demonstrates the ability of ovomucoid to trigger a mast cell-dependent allergic reaction in vivo.
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| ADME/Pharmacokinetics |
Chicken ovomucoid is a highly stable glycoprotein and is not typically administered systemically as a drug, so its pharmacokinetics in vivo are not a primary focus. In research models where it is administered intravenously to induce anaphylaxis, it distributes rapidly throughout the vasculature. It has a plasma half-life on the order of minutes to a few hours, primarily due to rapid clearance by the mononuclear phagocyte system (MPS) and proteolytic degradation. As a protein, it is not absorbed intact from the GI tract, which is a key reason it acts as a food allergen rather than a systemic toxin. When administered in research, its elimination is dominated by metabolism.
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| Toxicity/Toxicokinetics |
Chicken ovomucoid itself is not a drug and does not have toxicity in the classical sense; its primary pathological effect is the induction of IgE-mediated allergic reactions in sensitized individuals. As an allergen, it is a potent trigger for conditions ranging from mild oral allergy syndrome to life-threatening systemic anaphylaxis. For a non-sensitized individual or in laboratory use, it is considered of low acute toxicity, with no known genotoxicity or carcinogenicity. In its use as a laboratory protease inhibitor, it is handled as a standard laboratory chemical. It is neither a skin irritant nor a skin sensitizer in its purified form for non-allergic individuals. For impurity qualification, it is not considered a genotoxic impurity.
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| References |
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| Additional Infomation |
Chicken ovomucoid is a heat-stable, 186-amino acid glycoprotein with three tandem Kazal-type domains, each of which is stabilized by three intra-domain disulfide bonds. The third domain is the primary and most potent trypsin inhibitor, with a dissociation constant (Kd) in the picomolar to low nanomolar range. The molecule is heavily glycosylated, which contributes to its stability and allergenicity. As a major egg allergen, the majority of IgE antibodies from egg-allergic patients are directed against ovomucoid rather than the other egg white proteins, ovalbumin and ovotransferrin. For this reason, it is widely used in allergy research for epitope mapping and diagnostic test development. In a laboratory setting, it is used as a supplement in culture media to inhibit trypsin activity when passaging adherent cells, preventing cell detachment and damage. It is stored as a lyophilized powder at -20degC or below. Its high thermal stability means it retains its trypsin-inhibitory activity even after heating to 90degC for 30 minutes.
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| Appearance |
Light yellow to yellow liquid
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| Synonyms |
ovale mucins
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| Solubility (In Vivo) |
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.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *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). View More
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)] Oral Formulations
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). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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