| Description | Chimeric Rabies Virus Glycoprotein Fragment (RVG-9R), a chimeric peptide consisting of 29 amino acids, is synthesized by adding nona-arginine motif to the carboxy terminus of RVG (rabies virus glycoprotein ). Chimeric Rabies Virus Glycoprotein Fragment (RVG-9R) is positively charged and able to bindChimeric Rabies Virus Glycoprotein Fragment (RVG-9R), a chimeric peptide consisting of 29 amino acids, is synthesized by adding nona-arginine motif to the carboxy terminus of RVG (rabies virus glycoprotein ). Chimeric Rabies Virus Glycoprotein Fragment (RVG-9R) is positively charged and able to bind negatively charged nucleic acids via charge interaction... Read More | Purity>90% by SDS-PAGEExtinction Coeff.A280 nm = 0.988 at 1.0 mg/mLPrecautionsUse normal precautions for handling human blood productsGeneral DescriptionNative human C9 is a naturally glycosylated (7.8%) protein composed of a singlepolypeptide chain. The molecular weight is 71,000 Da. C9 binds toPurity>90% by SDS-PAGEExtinction Coeff.A280 nm = 0.988 at 1.0 mg/mLPrecautionsUse normal precautions for handling human blood productsGeneral DescriptionNative human C9 is a naturally glycosylated (7.8%) protein composed of a singlepolypeptide chain. The molecular weight is 71,000 Da. C9 binds to the C5b-8 complex and forms the mature membrane attack complex (MAC) on cell membranes. Each pathway of complement activation generates proteolytic enzyme complexes (C3/C5 convertases) which are bound to the target surface (Ross, G.D. (1986)). These enzymes cleave a peptide bond in the larger alpha chain of C5 releasing the anaphylatoxin C5a and activating C5b. This is the only proteolytic step in the assembly of the C5b-9 complex. C5b is unstable, but it remains bound to the activating complex for a brief time (~2 min) during which it either binds a single C6 from the surrounding fluid or decays and is no longer capable of forming MAC. The C5b,6 complex may also remain bound to the C3/C5 convertase where the binding of a single C7 exposes a membrane-binding region and C5b,6,7 can partially insert into the bilipid layer of the target cell. Up to this point the complex may diffuse away from the target cell and enter the membrane of a nearby cell. This is called bystander lysis or “reactive lysis” and can be a significant source of pathology. Each C5b-7 complex can bind one C8 protein molecule which results in the complex inserting more firmly into the membrane. The C5b-8 complex is capable of causing lysis without C9 although this is slow and requires many more complexes per cell than with C9. This property complicates C9 titrations since the precursor (C5b-8) can also cause lysis. The primary role of C8 is to catalyze the binding of C9 and each bound C9 can bind another C9 initiating formation of a ring structure containing up to 18 molecules of C9 (Podack, E.R. (1984)). C5b-9 complexes with one or more C9 are referred to as the Membrane Attack Complex (MAC) of complement. Not all C5b-8 complexes have complete rings of C9 with the average being only three C9 per C5b-8complex. Nevertheless, these structures are capable of causing lysis if enough are formed in a given cell. Completed protein rings of C9 form the pores seen on electron micrographs and they result in leakage of metabolites and small proteins out of the cell as well as movement of water into the cell. If sufficient numbers are inserted into a cell membrane then water flowing into the cell, due to osmotic pressure, will rupture the cell membrane allowing the entire contents of the target cell (or a bystander cell) to be released. Either process may result in cell death. Originally it was thought that this required only one C5b-9 complex per cell (referred to as the “one hit theory” of lysis (Rommel F.A. and Mayer, M.M. (1973)), but this is probably not correct. For example, an erythrocyte without CD59 requires ~850 C5b-9 complexes, as measured by the number of C7 molecules, for lysis to occur (Bauer, J. et al. (1979)). Host cells protected from MAC by CD59 require sufficient numbers of C5b-9 to tie up all the CD59 and then ~850 C5b-9 in addition. Lysis of nucleated cells requires many more C5b-9 complexes due to their size and due to the presence of multiple defense mechanisms in such cells.Physical Characteristics & StructureThe molecular weight of C9 is 71,000 Da and it is a single polypeptide chain. The protein contains 7.8% carbohydrate attached at two N-linked glycosylation sites. The pI of C9 is 4.7. C9 may polymerize spontaneously forming MAC rings without C5b-8. The rings formed from pure C9 as well as the completed rings formed by C5b-9 with 12 to 18 C9 molecules have the unusual property of being stable in boiling SDS even though they are non-covalently bound. Function See General Description above. Assays Assays for C9 function are complicated by the fact that if excess C5-C8 is used cells (EA or Er) will be lysed by the C5b-8 complex. Thus it is critical to use limited C8 in these assays to keep the background lysis to a minimum. The simplest assay for C9 is to use C9-depleted human serum and measure the lysis of EA (classical pathway) or Er (alternative pathway) as a function of the concentration of added test sample or standard purified C9. Each unique application might require appropriate conditions to be determined. However, a typical assay would involve mixing on wet ice ~5 µL C9-Dpl, C9-containing sample diluted with GVB⁺⁺ to contain from 1 to 10 ng C9, and sufficient GVB⁺⁺ to bring the volume to 300 µL. EA (3 X 10⁷ cells in 200 µL) diluted in GVB⁺⁺ should be added last. Purified C9 or normal human serum (NHS) may be used as a source of C9. The reaction mixture is incubated for 30 min at 37℃ and 1 mL of cold GVBE added, mixed and centrifuged to spin down unlysed cells. The released hemoglobin in the supernatant is then analyzed at 415 nm and compared to blanks without C9 (background lysis control) and cells incubated with 275 µL water instead of GVB⁺⁺ and 25 µL C9-Dpl (100% lysis control). Note as mentioned above, at inputs of serum higher than ~5 µL of C9-Dpl, EA and other target cells may also be lysed in the absence of C9 depending on the cells’ susceptibility to C5b-9.Many other assays have been described using EA preloaded with C1 (EAC1 cells) or preloaded with the classical pathway C5 convertase (EAC1423 cells), however, all these assays require the use of multiple purified complement components or more difficult-to-prepare reagents (Dodds, A.W. and Sim, R.B. (1997; Morgan, B.P. (2000);Tack, B.F., et al. (1981)).ApplicationsSee General Description aboveIn vivoThe normal serum concentration of C9 is 60 µg/mL (normal range 47 to 70µg/mL). The primary site of synthesis is the liver. C9 is also produced by monocytes, macrophages, fibroblasts and glial cells. C9 is an acute phase protein and its synthesis is stimulated by cytokines (such as IFNγ) that stimulate increased biosynthesis of many other complement proteins.RegulationMany proteins and other components of plasma have an inhibitory effect on the lytic activity of C5b-9 complexes but there are no specific C9 inactivators. Most of the C5b-9 inhibitors interact with the complex after the C5b-7 stage. If any of the C5bcontaining complexes fail to insert into a membrane they may self-aggregate or bind to regulatory proteins the most prevalent of which is S Protein. S Protein (also called vitronectin) is an 80,000 Da plasma protein found bound to most soluble C5b-9 complexes. Many other serum components inhibit or partially inhibit lysis by C5b-9 and these include SP40,40 (also known as clusterin and apolipoprotein J) and many plasma lipoprotein complexes (LDL, HDL, etc.).Host cells protect themselves from C5b-9 by a variety of mechanisms. Membrane proteins DAF, MCP, and CR1 inhibit formation of C3/C5 convertases preventing MAC formation. CD59, also called “homologous restriction factor” and “protectin”, is a 18,000 to 20,000 Da ubiquitous component of cell membranes that is very effective at binding to and inhibiting the lytic potential of C5b-8 and C5b-9 complexes. The speciesspecificity of CD59 is not absolute and many mammalian CD59 proteins inhibit or partially inhibit MAC from other species. The specificity that is observed appears to be due to incompatibilities between C8 of one animal and the CD59 of another. Like DAF, CD59 contains a GPI anchor (a post-translationally added lipid tail that inserts into the bilipid layer of the cell). The disease PNH is caused by the loss of enzymes that attach the GPI tail, thus depriving cells of the ability to express DAF and inactivate C3/C5 convertases and the ability express CD59 to inactivate C5b-9. This results in the spontaneous lysis by complement of the most susceptible cells such as erythrocytes and platelets.GeneticsHuman chromosome location 5p 13. Accession number HSC6A. Mouse chromosome 15. Human genomic structure: the gene spans 100 kb with 11 exons.DeficienciesHuman C9 deficiencies are quite common. A well documented study found that 1:1000 people in the Janaese population were C9 deficient although other ethnic groups have lower incidents of C9 deficiency (Horiuchi, T. et al. (1998)). Deficiencies exhibit autosomal recessive transmission. Patients generally exhibit abnormally high susceptibility to recurrent meningococcal meningitis and systemic neisserial infections. Partial deficiencies do not seem to show adverse clinical effects.DiseasesSee Deficiencies above.Precautions/Toxicity/HazardsThis protein is purified from human plasma, therefore precautions appropriate for handling any blood-derived product must be used even though the source was shown bycertified tests to be negative for HBsAg, HTLV-I/II, STS, and for antibodies to HCV, HIV-1 and HIV-II.Hazard Code: B WGK Germany 3MSDS available upon request... Read More | Purity>95% SDS-PAGE. FunctionIGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors. Promotes cell migration | Inquire | Vabicaserin hydrochloride is a 5-hydroxytryptamine 2C ( 5-HT 2C ) receptor -selective agonist with an EC 50 of 8 nM.In VitroVabicaserin displaces 125 I-(2,5-dimethoxy)phenylisopropylamine binding from human 5-HT 2C receptor sites in Chinese hamster ovary cell membranes with a K i value of 3 nM and Vabicaserin hydrochloride is a 5-hydroxytryptamine 2C ( 5-HT 2C ) receptor -selective agonist with an EC 50 of 8 nM.In VitroVabicaserin displaces 125 I-(2,5-dimethoxy)phenylisopropylamine binding from human 5-HT 2C receptor sites in Chinese hamster ovary cell membranes with a K i value of 3 nM and is >50-fold selective over a number of serotonergic, noradrenergic, and dopaminergic receptors. Binding affinity determined for the human 5-HT 2B receptor subtype using [ 3 H]5HT is 14 nM. Vabicaserin is a potent and full agonist (EC 50, 8 nM; E max, 100%) in stimulating 5-HT 2C receptor-coupled calcium mobilization and exhibits 5-HT 2A receptor antagonism and 5-HT 2B antagonist or partial agonist activity in transfected cells, depending on the level of receptor expression. Vabicaserin exhibits lower affinity at the 5-HT 2C antagonist binding site (22 nM) labeled with [ 3 H]mesulergine. Additional binding studies indicate that Vabicaserin possesses affinity for the 5-HT 2B and 5-HT 1A receptors with K i values of 14 and 112 nM, respectively. MCE has not independently confirmed the accuracy of these methods. They are for reference only.In VivoAfter a single oral dose of [ 14 C]Vabicaserin at 50, 5, and 15 mg/kg, unchanged drug represents less than 19, 20, and 35% of total plasma radioactivity at all the time points examined in mice, rats, and dogs, respectively. The carbamoyl glucuronide (CG) represents approximately 7 to 36% of plasma radioactivity in mice and 2 to 28% of plasma radioactivity in dogs but is not detected in rat plasma after the single [ 14 C]Vabicaserin dose. However, the CG is observed in rat plasma after multiple-dose administration of Vabicaserin at higher doses, and the CG is approximately 20 times less than Vabicaserin based on steady-state AUC 0-24 values. The estimated plasma AUC 0-24 ratios of CG to the parent drug are 1.5 and 1.7 in mice and dogs after the single [ 14 C]Vabicaserin dose, respectively. The plasma AUC 0-24 ratios for the CG to Vabicaserin at steady state with doses used for safety assessment are less for mice (0.2-0.6) and slightly higher for dogs (1.8-4.0) compared with the single dose values. The CG is detected in dog urine in similar amounts to the parent drug, although it is not detected in mouse or rat urine after the single [ 14 C]Vabicaserin dose. Radioactivity in a 0- to 24-h bile collection from rats receiving a 5 mg/kg [ 14 C]Vabicaserin dose accounts for 19 and 24% of the administered dose in males and females, respectively. Although the CG is not detected in urine or feces of rats after a single oral administration, it represents an average of up to 30% of biliary radioactivity in male rats and 15% in female rats. In monkeys after a single oral 25-mg/kg dose of Vabicaserin, the plasma concentrations of the CG exceeded those of Vabicaserin at all the time points (2-24 h) postdose, although the amount of CG relative to Vabicaserin decreased by 24 h postdose, with ratios of 17.5 at 2 h and 1.7 at 24 h. The CG to Vabicaserin AUC 0-24 ratio of 12:1 indicates that the CG is a major metabolite in monkeys. MCE has not independently confirmed the accuracy of these methods. They are for reference only.Animal administrationMice and Rats For metabolism studies in mice, rats, and dogs, radiolabeled doses are used. Male and female CD-1 mice and Sprague-Dawley rats are used. The dose vehicle for mice and rats contained 2% (w/w) Tween 80 and 0.5% methylcellulose in water. Nonfasted male and female mice weighing from 27.8 to 33.8 g at the time of dosing are given a single 50-mg/kg (∼300 µCi/kg) dose of Vabicaserin at a volume of 20 mL/kg via intragastric gavage. Mice are kept in metabolic cages in groups of five. Nonfasted male rats weighing from 318 to 345 g and female rats weighing from 227 to 255 g at the time of dosing are given a single 5-mg/kg (∼300 µCi/kg) dose of Vabicaserin at a volume of 2.5 mL/kg via intragastric gavage. Four bile duct-cannulated male rats weighing from 387 to 411 g and four bile duct-cannulated female rats weighing from 291 to 325 g at the time of dosing are nonfasted and are given a single 5-mg/kg (323 µCi/kg) dose of Vabicaserin at a volume of 5.0 mL/kg via intragastric gavage. Rats are kept individually in metabolism cages. Dogs Four male beagle dogs, weighing from 7.6 to 9.8 kg at the time of dosing, are from an in-house colony. Approximately 11 mg of [ 14 C]Vabicaserin hydrochloride and 940 mg of nonlabeled Vabicaserin hydrochloride are dissolved in methanol and then evaporated under a nitrogen stream to dryness. Capsules (number 2) are filled with accurate amounts (126.7-138.1 mg) of the mixed drug substance according to animal weights to give a dosage of 15 mg/kg (39 µCi/kg). The filled gelatin capsules are then enteric-coated manually. Each dog is given one enteric-coated capsule containing [ 14 C]Vabicaserin as the hydrochloride salt. Animals are fed 2 h before dosing and are housed individually in metabolic cages. Monkey Four male cynomolgus monkeys, weighing from 5.4 to 9.6 kg at the time of dosing, are from an in-house colony. Nonfasted monkeys are given a single 25-mg/kg dose of nonradiolabeled Vabicaserin at a volume of 2 mL/kg via intragastric gavage. The vehicle is the same as used in mice and rats. Animals are housed individually in metabolic cages. aladdin has not independently confirmed the accuracy of these methods. They are for reference only.IC50& Target:5-HT 2C Receptor 8 nM (EC 50 )... Read More |