| Description | FLAG peptide is an eight amino acids peptide (Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys) with an enterokinase-cleavage site; designed for antibody-mediated identification and purification of recombinant proteins.In VitroFusion protein technology has become an important tool for solving numerous problems FLAG peptide is an eight amino acids peptide (Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys) with an enterokinase-cleavage site; designed for antibody-mediated identification and purification of recombinant proteins.In VitroFusion protein technology has become an important tool for solving numerous problems linked to recombinant protein production. The properties of the additional tag facilitate identification and provide a one-step purification procedure of the fusion protein by passing cell extracts or supernatants through columns of an appropriate matrix. FLAG peptide allows elution under non-denaturing conditions. Several antibodies against FLAG peptide have been developed. One antibody, M1, binds the peptide in the presence of bivalent metal cations, preferably Ca 2+. Elution is effected by chelating agents. Another strategy is competitive elution with excess of free FLAGe peptide. Antibodies M2 and M5 are applied in this procedure. The Flag-tag is first described as a calcium-dependent epitope of a monoclonal antibody. It is a highly acidic octapeptide which can be N-terminally fused to the protein of interest. As a very hydrophilic peptide the Flag–tag has a high surface probability. Flag-fusion proteins can be captured by an immunoaffinity column in the presence of Ca 2+ and eluted byEDTA at low concentrations, neutral pH and thus, nearly physiological conditions. MCE has not independently confirmed the accuracy of these methods. They are for reference only.Form:Solid... Read More | Inquire | 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 | EPOCROSTM is a reactive polymer with an oxazoline group on the side chain and is used as a cross-linking agent for water-based resins. Among the water-based polymers developed to address environmental issues and the increasing use of water-based products due to VOC regulations and desolventing, the EPOCROSTM is a reactive polymer with an oxazoline group on the side chain and is used as a cross-linking agent for water-based resins. Among the water-based polymers developed to address environmental issues and the increasing use of water-based products due to VOC regulations and desolventing, the EPOCROSTM WS series is a “water-soluble type” with the following structure.Features and PropertiesHigher reactivity than water-based epoxy, melamine, blocked isocyanateVOC free (EPOCROS™ WS-300 and EPOCROS™ WS-700)High crosslinking density with a small amount addedOne-pack type with long usage timeImproves water resistance, solvent resistance, heat resistance, and the strength of films, etc.Adhesion-imparting possible to PET, OPP, PVC, etc.Fast dryingLow toxicity (Ames Test: Negative, Primary Skin Irritation Test: No irritation)WS Series Product LineupApplicationsNonwoven fabric bindersPigment printingCoatings (metals, films, leather)Paint and coatings, Primers (plastics, building materials, vehicles)AdhesivesMethodASSAY for Product Code DILW:One unit equals a decrease in absorbance of 1.0 per minute at 25°C at pH 7.5 with 2,6-dichlorophenolindophenol as the chromogen.Reagents0.2 M Tris⋅HCl buffer, pH 7.50.006 M NADH. Prepare fresh daily.0.0012 M Dichlorophenolindophenol (DCPIP) Prepare fresh daily.EnzymePrepare a 10 mg/ml solution of enzyme in 0.2 M Tris⋅HCl, pH 7.5.Dilute further immediately before use to give ΔA/min of 0.15-0.20.ProcedureAdjust spectrophotometer to 600 nm and 25°C.Pipette into cuvettes as follows:Mix quickly and measure the decrease in absorbance at 600 nm for 2-3 minutes.Determine the ΔA/min. from the initial linear portion of the curve. (Use portion of curve from t=0 to t=1 minute; the rate is linear for 1/2 to 1 minute.)Calculation... Read More | Store at +4°C. Store under desiccating conditions. The product can be stored for up to 12 months |