| Description | AEN Human Pre-designed siRNA Set A contains three designed siRNAs for AEN gene (Human), as well as a negative control, a positive control, and a FAM-labeled negative control. Components AEN siRNA-1: 5 nmol (HPLC) AEN siRNA-2: 5 nmol (HPLC) AEN siRNA-3: 5 nmol (HPLC) siRNA Negative Control: 5 nmol (AEN Human Pre-designed siRNA Set A contains three designed siRNAs for AEN gene (Human), as well as a negative control, a positive control, and a FAM-labeled negative control. Components AEN siRNA-1: 5 nmol (HPLC) AEN siRNA-2: 5 nmol (HPLC) AEN siRNA-3: 5 nmol (HPLC) siRNA Negative Control: 5 nmol (HPLC) FAM-labeled siRNA Negative Control: 5 nmol (HPLC) GAPDH siRNA Positive Control:5 nmol (HPLC)... 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 | Protein Purity>97% by SDS-PAGEExtinction Coeff.A280 nm = 0.41 at 1.0 mg/mlMolecular Weight10,400 Da (single chain)General DescriptionNatural human C5a is prepared from human C5 protein by cleavage of the peptide bond between C5a and C5b by the human C5 convertase. C5a is a naturally glycosylated Protein Purity>97% by SDS-PAGEExtinction Coeff.A280 nm = 0.41 at 1.0 mg/mlMolecular Weight10,400 Da (single chain)General DescriptionNatural human C5a is prepared from human C5 protein by cleavage of the peptide bond between C5a and C5b by the human C5 convertase. C5a is a naturally glycosylated polypeptide containing 74 amino acids with a molecular weight of approx. 10,400 daltons. Itcontains 25% carbohydrate attached to a single Asn residue at position 64. This carbohydrate is of variable structure leading to a broad distribution of MW upon analysis by mass spectroscopy. C5a is the most potent anaplylatoxin (compared to C3a and C4a). Its biological properties include being strongly chemotactic for neutrophils (PMN), causing smooth muscle contraction, increasing vascular permeability, causing histamine and TNFalpha release, and causing lysosomal degranulation of immune cells. C5a acts through the C5a Receptor (C5aR, CD88, a G-protein coupled receptor) on PMN, monocytes, alveolar macrophages, and mast cells. A second receptor of unknown function (C5L2, gpr77) has been identified. Due to the widespread expression of C5a receptors and the results from C5aR KO mice it is believed that C5a and its receptors have many non-immunolgical functions in organ development, CNS development, neurodegeneration, tissue regeneration and hematopoiesis (Monk, P.N. et al. (2007)).Native versus Recombinant C5aNumerous recombinant forms of C5a are sold by many companies. In side-by-side biological testing, we have found that our native C5a is 10- to 100-fold more active per µg than all but one of these recombinant proteins. Structurally not a single one of the recombinant proteins on the market has the correct amino acid sequence or structure. They have extra amino acids at the N-terminal (such as 6 His tags), different amino acids in the sequence itself (some were produced from the original, but incorrect amino acid sequence), and none possess the 25% carbohydrate at Asn 64. In fact, one recombinant C5a on the market has approximately 30 additional amino acids at the N-terminal end due to the cloning vector used. This is a 40% addition of nonsense structure to the C5a molecule. Both our C5a and our C5adesArg are native proteins produced by the native human C5 convertase. Physical Characteristics & StructureMolecular weight: 10,400 (+ 1,000 due to variable glycosylation)Deglycosylated MW: 8,271 (observed). Calculated monoisotopic mass 8268;Calculated average mass 8273.Isoelectric point: pI = 8.9Carbohydrate content: ~25% carbohydrate (heterogeneous) Amino acid sequence: TLQKKIEEIA AKYKHSVVKK CCYDGACVNNDETCEQRAAR ISLGPRCIKA FTECCVVASQ LRANISHKDM QLGRCAS Number: 80295-54-1MDL Number: MFCD00130842NMRderived structure: FEBS Lett. 238:289-294, 1988; Biochemistry 28:172-185,1989; Biochemistry 29:2895-2905, 1990; Proteins 28:261-267, 1997.FunctionC5a released from C5 by C5 convertases initiates a multitude of inflammatory reactions. C5a causes neutrophils to become adherent to endothelium and to migrate to the site of complement activation by chemotaxis where it stimulates release of PMN granule contents and reactive oxygen species. The biological properties of C5a include being strongly chemotactic for neutrophils (PMN), causing smooth muscle contraction, increasingvascular permeability, causing histamine release, and initiating lysosomal degranulation of a variety of immune cells. C5a acts through the C5a Receptor (C5aR, a G-protein coupled receptor) on PMN, monocytes, alveolar macrophages, dendritic cells, mast cells, glial cells and smooth muscle cells. Rapid release of C5a and other anaphylatoxins can cause systemic effects as well as local changes. Anaphylatic shock is a generalized circulatory collapse similar to that caused by an allergic reaction and is caused by C3a and C5a which are generally released together. AssaysThe multitude of biological functions of C5a has resulted in the use of many different assay systems (Dodds, A.W. and Sim, R.B. (1997)). The most typical biological assays being smooth muscle contraction assays using guinea pig ileum, chemotaxis assays using neutrophils or granule-release assays using human PMN or similar cell lines. Granule release is generally followed by measuring the release of myeloperoxidase. In addition, assays have been described that measure ATP release from guinea pig platelets, serotonin relaease from guinea pig platelets, N-acetyl-beta-D-glucosamidase release from differentiated U937 cells and calcium release from differentiated U937 cells. These assays have been described in detail (Dodds, A.W. and Sim, R.B. (1997)). Functional responses have been detected in the sub-picomolar concentration range for purified human C5a (Gerard, C. et al. (1981); Hugli, T.E. et al. (1981)).ELISA kits for the assay of C5a levels (or more correctly C5a desArg levels) in blood and other fluids are sold by many companies. A radioimmunoassay for C5a/C5a desArg is also available. 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 vivoThe resting serum concentration has been reported to be approximately 4 nMalthough it is difficult to draw or store blood without 1 to 10 % C5 activation (Watkins, J.(1987)). The presence of EDTA and Futhan in the collection tubes can minimize this background. Full activation of all C5 in blood (75 µg/mL) would result in ~380 nM C5a(~3.9 µg/mL). Due to the extreme sensitivity of many C5a responses, a response can theoretically be initiated by activation of approximately one millionth of the C5 in a local area.RegulationC5a levels are regulated by three processes: formation, inactivation and clearance. The enzymes that cleave C5 and release C5a (collectively called C5 convertases) do so at very slow rates. Operating at Vmax the best enzymes only cleave one C5 every three minutes (Rawal, N. and Pangburn, M.K. (2001)). C5a is “inactivated” by removal of its Cterminal arginine amino acid. The product C5a desArg (or C5a without the C-terminal arginine) is produced by the action of the plasma enzyme carboxypeptidase N (Mueller-Ortiz S.L. et al. (2009)). This inactivation is rapid and most C5a is converted to C5a desArg within minutes of its formation. “Inactivated” C5a still possesses approx. 1% of its anaphylatoxic and chemotatic activities, but its stimulatory activity is only reduced 10-fold. Thus, C5a desArg retains considerable biological activity even though it is frequently called inactivated C5a. Because of the large number of cells bearing C5a receptors (endothelial, immune, smooth muscle, neuronal, etc.) the capture, internalization and digestion of C5a results in its rapid removal from circulation.DeficienciesA deficiency of C5 or a deficiency of the enzymes that cleave C5 to generate C5a result in the absence of C5a. There are no known complete deficiencies of C5 convertases. Examples of C5 deficient humans and mice exist. In fact, many laboratory mouse strains in common use were shown to have been bred with a deficiency of C5 (A/HeJ, AKR/J, DBA/2J, NZB/B1NJ, SWR/J, and B10.D2/nSnJ). The lack of C5 prevents formation of the membrane attack complex of complement and precludes formation of C5a. Humans lacking C5 are susceptible to repeated infections from a wide variety of organisms, primarily gramnegative bacteria. Meningococcal and gonococcal neisserial infections are especially problematic. The degree to which pathologies associated with C5 deficiency are due to the lack of C5 or the absence of C5a is unclear, but information on this is being acquired from receptor knock-out animals.DiseasesSee Deficiencies above.Precautions/Toxicity/HazardsThis protein is purified from human serum and therefore precautions appropriate for handling any blood-derived product must be used 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 Characteristics UNI-StabilPLUS is a universal stabilizer for the dilution and stabilization of both Horseradish Peroxidase (HRP) and Alkaline Phosphatase (AP) labeled proteins and antibodies, in order to maintain the molecular conformation and prevent loss of activity over time. This enablesProduct Characteristics UNI-StabilPLUS is a universal stabilizer for the dilution and stabilization of both Horseradish Peroxidase (HRP) and Alkaline Phosphatase (AP) labeled proteins and antibodies, in order to maintain the molecular conformation and prevent loss of activity over time. This enables the making of pre-diluted, ready-to-use conjugates, minimizing assay errors in dilution. Superior stabilization of HRP and AP conjugated antibodies in low as well as high protein dilutions is seen, when using UNI-StabilPLUS. When tested with AP conjugated antibody stability is seen as follows: • at least 3 years at 2-8 °C • at least 2 years at room temperature • at least 4 weeks at 37 °C When tested with HRP conjugated antibody stability is seen as follows: • at least 2 years at 2-8 °C • at least 1 years at room temperature • at least 2 weeks at 37 °CUNI-StabilPLUS is recommended for the dilution of antibodies directed against rabbit immunoglobulins unlike HRP-StabilPLUS (cat. no. H494387) and Antibody Enhancer (cat. no. A494276).Composition & Properties UNI-StabilPLUS is a ready-to use buffer that appears as an opaque solution. The product is based on a mild acid Tris buffer containing proprietary stabilizing components. UNI-StabilPLUS contains neither BSA, nor other material from bovine serum, no azide, mercury or other toxic components.Working Procedure 1.Make a series of dilutions of the HRP- or AP conjugated protein in UNI-StabilPLUS in order to determine the optimal dilution. 2.Run the assay as usual or store the diluted conjugated protein preferably at 2-8 °C.Tips & Tricks • Avoid using phosphate buffers for AP-conjugated antibody assays. We recommend the use of Tris/HCl, Tween as the washing buffer, instead of a PBS buffer which will reduce signal significantly. • For extended stability of HRP conjugated antibodies, HRP-StabilPLUS (cat. no. H494387) is recommended. Handling & Storage • Store solution at 2-8 °C... Read More |