| Description | The Flag tag is an octapeptide composed of hydrophilic amino acids, strategically positioned on the surface of fusion proteins. This location facilitates easier binding to antibodies and cleavage by enterokinase. Anti-Flag Agarose Resin utilizes an anti-Flag (DYKDDDDK) antibody as the affinity The Flag tag is an octapeptide composed of hydrophilic amino acids, strategically positioned on the surface of fusion proteins. This location facilitates easier binding to antibodies and cleavage by enterokinase. Anti-Flag Agarose Resin utilizes an anti-Flag (DYKDDDDK) antibody as the affinity ligand for the one-step purification of Flag-tagged fusion proteins expressed in prokaryotic, yeast, or mammalian cell systems. This product is based on a 4% agarose gel matrix, which minimizes non-specific binding of host cell proteins, making it suitable for both the purification and immunoprecipitation (IP) of Flag-tagged fusion proteins. Aladdin Anti-Flag Agarose Resin is stored in a solution containing 0.1% ProClin 300, with a settled gel to storage solution ratio of 1:1. The product specification refers to the actual volume of the settled gel.ParameterValue / DescriptionMatrix4% Agarose MicrospheresLigandAnti-DYKDDDDK AntibodyParticle Size Range45~165 µmBinding Capacity>1 mg DYKDDDDK-tagged protein / mL resinMaximum Pressure0.1 MPa, 1 barStorage Conditions0.1% ProClin 300, 2~8℃Shelf Life2 yearsProtocol1. Sample PreparationEnsure the sample solution has appropriate ionic strength and pH before loading. Dilute the sample or cell culture supernatant with equilibration buffer, or dialyze the sample against equilibration buffer.Clarify the sample by centrifugation or filtration through a 0.22 µm or 0.45 µm membrane to reduce impurities, improve purification efficiency, and prevent column clogging.2. Buffer PreparationIt is recommended to filter water and buffers through a 0.22 µm or 0.45 µm membrane before use.Equilibration/Wash Buffer: 50 mM Tris, 0.15 M NaCl, pH 7.4Acidic Elution Buffer: 0.1 M Glycine-HCl, pH 3.0Competitive Elution Buffer: 50 mM Tris, 0.15 M NaCl, 100-500 µg Flag peptide / mL, pH 7.4Neutralization Buffer: 1 M Tris-HCl, pH 8.03. Sample Purification3.1 Column Chromatography(1) Pack the Anti-Flag Agarose Resin into a suitable chromatography column. Equilibrate the column with 5 column volumes (CV) of Equilibration Buffer to bring the resin into the same buffer system as the target protein.(2) Load the sample onto the equilibrated Anti-Flag Agarose Resin. Collect the flow-through. The sample can be reloaded to increase binding efficiency.(3) Wash with 10 CV of Wash Buffer to remove non-specifically bound proteins. Collect the wash fractions.(4) Elution:* A. Acidic Elution: Elute with 5 CV of Acidic Elution Buffer. Add a volume of Neutralization Buffer equal to one-tenth of the elution volume to each fraction to adjust the pH to 7.0–8.0. Collect fractions separately.* Note: After acidic elution, the resin must be immediately re-equilibrated. Do not expose the Anti-Flag Agarose Resin to the acidic elution buffer for more than 20 minutes.*** B. Competitive Elution: Elute with 5 CV of Competitive Elution Buffer. Collect fractions separately.(5) Regenerate the resin with 3 CV of the respective Elution Buffer, then re-equilibrate with Equilibration Buffer until neutral pH is reached.(6) Store the resin in Storage Buffer at 2–8°C.3.2 Batch/Binding Method(1) Resin Preparation: Transfer an appropriate amount of Anti-Flag Agarose Resin to a column and drain the storage solution. Wash with 5 CV of Equilibration Buffer.(2) Add the sample solution. Incubate with shaking at 4°C or room temperature for at least 30 minutes (avoid magnetic stirring). Ensure thorough mixing of the resin and sample.(3) After incubation, centrifuge the mixture (5,000 × g, 1 min) or filter to collect the resin.(4) Transfer the resin to a column. Wash with Equilibration Buffer until the UV baseline stabilizes.(5) Elute using either the Acidic or Competitive Elution method as described in section 3.1 (4).(6) Regenerate and store the resin as described in sections 3.1 (5) and (6).3.3 Immunoprecipitation (IP) Procedure(1) Resin Preparation: Add 40 µL of Anti-Flag Agarose Resin suspension (20 µL settled resin) to a 2 mL tube. Centrifuge at 5,000 × g for 1 min. Carefully remove and discard the supernatant.(2) Add 0.5 mL of Equilibration Buffer to resuspend the resin (this brings it into the correct buffer system, protecting the protein). Centrifuge at 5,000 × g for 1 min. Discard the supernatant. Repeat this wash step once.(3) Add 200–1000 µL of sample lysate to the prepared resin. Mix thoroughly and incubate on a tube rotator or roller mixer at room temperature for at least 1 hour to facilitate binding. Centrifuge at 5,000 × g for 1 min. Discard the supernatant.(4) Washing: Add 0.5 mL of Wash Buffer, resuspend the resin, and mix gently. Centrifuge at 5,000 × g for 1 min. Discard the supernatant. Repeat this wash step three more times to ensure removal of non-specifically bound material.(5) Elution: Choose the elution method based on downstream application requirements.* A. Acidic Elution: Add 100 µL of Acidic Elution Buffer and resuspend the resin. Incubate at room temperature for 5 min. Centrifuge at 5,000 × g for 1 min. Carefully collect the supernatant without disturbing the resin. Neutralize immediately with Neutralization Buffer. Store eluted samples at 4°C short-term or -20°C long-term.* B. Competitive Elution: Add 100 µL of Competitive Elution Buffer and resuspend the resin. Incubate at room temperature for 30 min. Centrifuge at 5,000 × g for 1 min. Carefully collect the supernatant. Store eluted samples at 4°C short-term or -20°C long-term.* C. Denaturing Elution (SDS-PAGE): Standard protein loading buffer (containing β-mercaptoethanol/DTT and SDS) will denature the anti-Flag antibody, releasing the bound protein but rendering the resin unusable for reuse. Add 20 µL of 2× Loading Buffer to the resin, heat at 95°C for 5 min. Centrifuge at 5,000 × g for 1 min, and load the supernatant directly onto an SDS-PAGE gel for analysis.Reagent CompatibilityReagentMaximum Tolerant ConcentrationNotesβ-Mercaptoethanol10 mMAvoid during purification; if used in IP, resin cannot be reusedDTT80 mMAvoid during purification; if used in IP, resin cannot be reusedSDS--Avoid during purification; if used in IP, resin cannot be reusedEDTA5 mMHigher concentrations reduce protein recoveryTween-205%High concentrations may reduce binding efficiencyTriton X-1005%High concentrations may reduce binding efficiencyNP-404%High concentrations may reduce binding efficiencyGuanidine HCl0.3 MHigher concentrations denature the antibodyUrea1.5 MHigher concentrations denature the antibodyGlycerol20%High concentrations may affect protein bindingNaCl1 MHelps reduce non-specific adsorptionTroubleshooting Guide... Read More | Protein Purity>95% by SDS-PAGEExtinction Coeff.A276 nm = 0.456 at 1.0 mg/mLMolecular Weight8,759 Da (single chain)General DescriptionNatural human C4a is prepared by cleavage of human C4 protein by human C1s. It is produced during activation of both the classical and lectin pathways of complementProtein Purity>95% by SDS-PAGEExtinction Coeff.A276 nm = 0.456 at 1.0 mg/mLMolecular Weight8,759 Da (single chain)General DescriptionNatural human C4a is prepared by cleavage of human C4 protein by human C1s. It is produced during activation of both the classical and lectin pathways of complement. C4a is a member of the anaphylatoxin family of three proteins (C3a, C4a and C5a) produced by the activation of complement (Hugli, T.E. et al. (1981)). It is an unglycosylated polypeptidecontaining 77 amino acids with a molecular mass of 8,759 daltons. Many of the biological functions of C4a are similar to those of C3a, but the specific activities are far below those of C3a. C4a activity is so low, in fact, that it was initially thought to be inactive. These measured activities include inducing muscle contraction in the guinea pig ileum test (spasmogenic activity), desensitization of muscle to C3a stimulation suggesting that the same receptor for both C3a and C4a is involved (tachyphylactic activity) and inducing vascular permeability in human skin (Gorski J.P. et al. (1979)). C4a does not show tachyphylactic activity against C5a or chemotactic activity. Removal of the C-terminal arginine by serum carboxypeptidase N destroys all these activities (Meuller-Ortiz, S.L., et al. (2009)). C4a appears to act through the C3a receptor (C3aR) which is a G-protein coupled receptor found widely distributed on peripheral tissues, lymphoid cells (neutrohphils, monocyes, and eosinophils) and in the central nervous system (astrocytes, neurons and glial cells) (Law, S.K.A. and Reid, K.B.M. (1995)). Physical Characteristics & StructureMolecular weight: 8,759 calculated molecular mass. Observed mass (MALDI-TOF) is 8,762 + 9 mass units. pI = 9.0 to 9.5 (Gorski, J.P. et al. (1981))Amino acid sequence (77 amino acids): NVNFQKAINE KLGQYASPTA KRCCQDGVTR LPMMRSCEQR AARVQQPDCR EPFLSCCQFA ESLRKKSRDK GQAGLQRC4a is thought to be structurally very similar to C3a and C5a to which it is homologous. Thus its 3D structure is probably similar to the X-ray-derived crystal structureof C3a (Huber, R. et al. (1980)) and the NMR derived structure of C3a: Nettesheim, D.G. et al. (1988); Murray, I. et al. (1999).FunctionSee General Description above. C4a exhibits much weaker biological activities than C3a and C5a. Its activity in inducing erythema and edema in human skin is 25,000-fold weaker than that of C5a and 100-fold weaker than C3a per nanomole. The spasmogenic activity of C4a is 2000-fold weaker than C5a and 100-fold weaker than that of C3a. Due to these differences the role of C4a in these responses in vivo is thought to be negligible.AssaysTwo well established assays for C4a and C3a functional activities include induction of contraction in the guinea pig ileum and the permeation of a dye such as trypan blue from the vasculature into skin. The anaphylatoxins also induce mast cell degranulation, (measured as histamine release), platelet aggregation, IL-1 release from monocytes and the release of prostaglandins and leukotrienes from many cells and tissues. The other assays used for C3a (Dodds, A.W. and Sim, R.B. (1997)) should also respond to C4a, but few reports have described utilizing these assays with C4a. ELISA kits for the assay of C4a levels (or more correctly C4a desArg levels) in blood and other fluids are sold by several companies. These measurements are useful for detecting complement activation in vivo, but the interpretation of their meaning is complicated by the fact that clearance of the anaphylatoxins is rapid. In vivoFreshly drawn normal human serum contains significant levels of all three anaphylatoxins. Although these may represent the resting concentration in vivo it is difficult to draw or store blood without some complement activation so a true in vivo concentration is difficult to determine. The presence of EDTA and Futhan in the collection tubes can minimize this background (Pfeifer, P.H. et al. (1999)). Full activation of all C4 in blood (600µg/mL) would result in ~3,400 nM C4a (~30 µg/mL). Due to the low biological activity of C4a it could require activation of most of the C4 in a small region to achieve the micromolar C4a concentrations necessary to elicit a response.RegulationC4a levels are regulated by three processes: formation, inactivation and clearance. There are two enzymes that cleave C4 and release C4a: C1s and MASP-2. C4a is “inactivated” by removal of its C-terminal arginine amino acid. The product C4a desArg (or C4a without the C-terminal arginine) is produced by the action of the plasma enzyme carboxypeptidase N (Mueller-Ortiz S.L. et al. (2009)). The inactivation is rapid and most C4a is converted to C4a desArg within minutes of its formation. Inactivated C4a lack measurable biological activity. Because of the large number of cells bearing C3a/C4areceptors (endothelial, immune, smooth muscle, neuronal, etc.) the capture, internalization and digestion of C4a and C4a desArg probably results in its removal from circulation.DeficienciesA deficiency of C4 or a deficiency of all of the enzymes that cleave C4 to generate C4a could result in the absence of C4a. There are no known complete deficiencies of all ofthe C4 cleaving enzymes. Examples of C4 deficient humans and mice exist (Wessels, M.R. et al. (1995)), but the degree to which pathologies associated with C4 deficiency are due to the lack of C4 or the absence of C4a is unclear. DiseasesThere are no known diseases connected to C4a or C4a desArg. Precautions/Toxicity/HazardsThe source of C4a is human serum, therefore appropriate precautions must be observed even though the source was shown by certified tests to be negative for HBsAg, HTLV-I/II, STS, and for antibodies to HCV, HIV-1 and HIV-II.Injection can cause anaphylatic shock which is a generalized circulatory collapse similar to that caused by an allergic reaction.Hazard Code: B WGK Germany 3... Read More | Nucleoprotein (396-404) is the 396 to 404 fragment of lymphocytic choriomeningitis virus (LCMV). Nucleoprotein (396-404) is the H-2D(b)-restricted immunodominant epitope and can be used as a molecular model of viral antigen.Form:Solid | Aprotinin is a competitive serine protease inhibitor that inhibits trypsin,chymotrypsin,kallikrein and plasmin.Aprotinin forms stable complexes with and blocks the active sites of enzymes. Binding is reversible with most aprotinin,protease complexes and dissociating at pH >10 or <3. Effective Aprotinin is a competitive serine protease inhibitor that inhibits trypsin,chymotrypsin,kallikrein and plasmin.Aprotinin forms stable complexes with and blocks the active sites of enzymes. Binding is reversible with most aprotinin,protease complexes and dissociating at pH >10 or <3. Effective concentration is equimolar with protease.Recombinant aprotinin is expressed in E. Coli, and purified with HPLC. It contains no animal-derived components. This is a recombinant form of bovine lung aprotinin, which is traditionally isolated from bovine lung by methods involving fractional precipitation, gel filtration, and ion exchange chromatography. UNIT DEFINITION:A conversion factor for Aprotinin is: 1 EPU = 1 USP Aprotinin Unit = 1800 KIU... Read More | Purity> 95% by SDS-PAGE and HPLC analyses.FunctionSerine protease inhibitor that inhibits plasminogen activators and plasmin but not thrombin. May be involved in the formation or reorganization of synaptic connections as well as for synaptic plasticity in the adult nervous system. May protect Purity> 95% by SDS-PAGE and HPLC analyses.FunctionSerine protease inhibitor that inhibits plasminogen activators and plasmin but not thrombin. May be involved in the formation or reorganization of synaptic connections as well as for synaptic plasticity in the adult nervous system. May protect neurons from cell damage by tissue-type plasminogen activator... Read More |