| Description | GIP (3-42), human acts as a glucose-dependent insulinotropic polypeptide (GIP) receptor antagonist, moderating the insulin secreting and metabolic actions of GIP in vivo.In VitroThe incretin hormone GIP is rapidly degraded in the circulation by dipeptidyl peptidase IV (DPP IV) forming the N-GIP (3-42), human acts as a glucose-dependent insulinotropic polypeptide (GIP) receptor antagonist, moderating the insulin secreting and metabolic actions of GIP in vivo.In VitroThe incretin hormone GIP is rapidly degraded in the circulation by dipeptidyl peptidase IV (DPP IV) forming the N-terminally truncated peptide GIP(3-42). 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 | Inquire | Product contentF665766Component5 mLStorageF665766A2×Fast Probe Mixture5×1 mL-20℃. Avoid freeze/thaw cycle.F665766BddH2O5×1 mL-20℃. Avoid freeze/thaw cycle.Product IntroductionFast Probe Mixture is a pre-mixed system for real-time fluorescence PCR by probe method (TaqMan, Product contentF665766Component5 mLStorageF665766A2×Fast Probe Mixture5×1 mL-20℃. Avoid freeze/thaw cycle.F665766BddH2O5×1 mL-20℃. Avoid freeze/thaw cycle.Product IntroductionFast Probe Mixture is a pre-mixed system for real-time fluorescence PCR by probe method (TaqMan, Molecular Beacon, etc.), with a concentration of 2×, including Fast Taq DNA Polymerase, PCR Buffer, dNTPs, Mg2+ and so on, which is easy and convenient to operate. It is mainly used for the detection of genomic DNA target sequence and cDNA target sequence after RNA reverse transcription. The Fast Taq DNA Polymerase contained in this product can effectively reduce the non-specific amplification generated by the non-specific binding of primers and templates or primer dimerization at room temperature, and the activation of the enzyme only needs to be incubated at 95 ℃ for 30 s. The whole PCR reaction process can save about 40 minutes compared with the ordinary reaction, which greatly shortens the reaction time of PCR. The combination of unique PCR buffer system and fast hot start enzyme effectively inhibits the generation of non-specific products and significantly improves the PCR amplification efficiency with stronger fluorescence signal, higher sensitivity and wider linear range. The product has a wide range of applications and can be used for both normal and rapid quantitative PCR programs.ROX dye is used to correct the fluorescence signal error generated between wells of a quantitative PCR instrument, and is generally used in Real Time PCR amplifiers from ABI, Stratagene, and other companies. The excitation optics vary from instrument to instrument, so the concentration of ROX dye must be matched to the corresponding fluorescence quantitative PCR instrument.Instruments that do not require ROX calibration (F665766):Roche LightCycler 480, Roche LightCyler 96, Bio-rad iCyler iQ, iQ5, CFX96 and others.Instruments that require Low ROX calibration (F665768):ABI Prism7500/7500 Fast, QuantStudio®3 System, QuantStudio®5 System, QuantStudio®6 Flex System, QuantStudio®7 Flex System, ViiA 7 system. Stratagene Mx3000/Mx3005P, Corbett Rotor Gene 3000, and more.Instruments that require High ROX calibration (F665774):ABI Prism 7000/7300/7700/7900, Eppendorf, ABI Step One/Step One Plus, and others.matters needing attention1. Before use, please mix gently by turning up and down, avoid foaming as much as possible, and use after brief centrifugation.2. Avoid repeated freezing and thawing of this product, repeated freezing and thawing may degrade the product performance. This product can be stored for long term at -20℃, protected from light. If frequent use is required within a short period of time, it can be stored at 2-8℃.UsageThe following examples are conventional PCR reaction systems and reaction conditions, which should be improved and optimized according to the template, primer structure and target fragment size in actual operation.1.PCR reaction systemReagents50 µl Reaction systemFinal concentration2×Fast Probe Mixture25 µl1×Forward Primer，10 µM1 µl0.2 µM¹⁾Reverse Primer，10 µM1 µl0.2 µM¹⁾Probe，10 µM1 µl0.2 µM²⁾Template DNA2 µl³⁾ 50×Low ROX or High ROX（optional）⁴⁾1 µl1×ddH₂Oup to 50 µlNote: 1) Usually the primer concentration of 0.2µM can get better results, and 0.1-1.0µM can be used as a reference for setting the range. 2) The final concentration of the probe used is related to the fluorescent quantitative PCR instrument used, the type of probe, and the type of fluorescent labeling substance, so please refer to the instruction manual of the instrument or the specific requirements of the use of each fluorescent probe for the adjustment of the concentration in actual use.(3) Usually the amount of DNA template is 10-100ng genomic DNA or 1-10ng cDNA as a reference. Since the templates of different species contain different copy numbers of target genes, the templates can be subjected to gradient dilution to determine the optimal amount of template to be used.(4) The excitation optical system varies from instrument to instrument, choose to add 50×Low ROX or 50×High ROX according to the instrument using fluorescence quantification.2. PCR reaction program:A two-step PCR reaction program is recommended, and this program is set up using the ABI 7500 Fluorescent Quantitative PCR Instrument as a reference.Note: 1) The enzyme used in this product must be pre-denatured at 95°C for 30s to achieve enzyme activation. Under this condition, most of the templates can be well unchained. For templates with high GC content and complex secondary structure, the pre-denaturation time can be extended to 1-4 minutes in order to make the starting template fully unchained.(2) It is recommended to use two-step PCR reaction program, if you can not get good experimental results due to the use of primers with lower Tm values, etc., you can try to carry out a three-step PCR amplification, annealing temperature, please use the range of 56 ℃ - 64 ℃ for as a reference for the setting... Read More |