| Description | β-Melanocyte Stimulating Hormone (MSH), human, a 22-residue peptide, acts as an endogenous melanocortin-4 receptor ( MC4-R ) agonist | 4-Methylumbelliferyl α-L-iduronide (free acid) is a fluorogenic substrate for α-L-iduronidase. This is found in cell lysosomes, which is involved in the degradation of glycosaminoglycans. 4-Methylumbelliferyl-α-L-iduronide is cleaved by α-L-iduronidase to release the fluorescent 4-Methylumbelliferyl α-L-iduronide (free acid) is a fluorogenic substrate for α-L-iduronidase. This is found in cell lysosomes, which is involved in the degradation of glycosaminoglycans. 4-Methylumbelliferyl-α-L-iduronide is cleaved by α-L-iduronidase to release the fluorescent moiety 4-methylumbelliferyl (4-MU). This 4-Methylumbelliferyl α-L-iduronide form is the free acid, which offers a considerable weight for weight advantage over the 4-MU iduronide salt in terms of its application dose.:For further studies, use α-L-iduronidase gene silencing:siRNA and shRNA:reagents and α-L-iduronidase gene editing:CRISPR:knockout and activation products... Read More | Protein Purity≥85% by SDS PAGEExtinction CoeffA280 nm = 0.631 at 1.0 mg/ml for pure C1qMolecular Weight400,000 Da (18 chains)General DescriptionRat C1q is purified from pooled normal rat serum. C1q is part of the C1 complex, which is the first complement component in the classical pathway of Protein Purity≥85% by SDS PAGEExtinction CoeffA280 nm = 0.631 at 1.0 mg/ml for pure C1qMolecular Weight400,000 Da (18 chains)General DescriptionRat C1q is purified from pooled normal rat serum. C1q is part of the C1 complex, which is the first complement component in the classical pathway of complement. The C1 complex is a non-covalent assembly of three different proteins (C1q, C1r, and C1s) bound together in a calcium-dependent complex. C1q has six extended arms with domains at the end of each arm that bind to the Fc domains of immunoglobulins such as IgG or IgM. When antibodies bind toantigens, forming immune complexes, they cluster allowing two or more of the six C1q arms to bind to the Fc domains of antibodies. Rat IgG2 is very efficient when compared to IgG1 in activating complement (Medgyesi, G.A et., al., 1981). This is in contrast to the human system in which IgG1 activates complement but not IgG2 (Redpath, S. et. al., 1998). The binding of multiple arms of C1q to immune complexes causes the two C1r proteins in the complex (protease zymogens) to auto-activate. The activated C1r proteases cleave and activate the two C1s protease zymogens in the complex. The activated C1s cleaves complement component C4 releasing C4a and initiating covalent attachment of C4b to the activating surface. Activated C1s also cleaves C2 and the larger fragment of C2 binds to the surface-attached C4b forming C4b,C2a, the C3/C5 convertase of the classical pathway.Rat IgG1 cannot activate complement whereas rat IgG2 does.Physical Characteristics & StructureThe apparent molecular weight of rat C1q as determined by gel filtration has been reported to be 400,000 by Veerhuis, R. et al., (1985) and is calculated to be 420,000 based on its amino acid sequence. Rat C1q is a high molecular weight complex of 18 polypeptide chains. Each of the six arms of rat C1q contains three chains, an A chain (~30,000 daltons), a B chain (~28,000 daltons) and a C chain (~26,000 daltons) as determined by SDS/polyacrylamide gel electrophoresis (Wing, M.G. et al., (1993)).FunctionThe biological functions of C1q are described above in the General Description and Physical Characteristics sections.ApplicationsRat C1q can be used to coat ELISA plates to capture and quantitate immune complexes in samples from rat models used for studying immune complex related diseases and conditions.GeneticsNCBI Gene ID numbers for rat C1q are: C1q A chain (298566), C1q B chain (29687), and C1q C chain (362634). The genes for C1q chains A, B and C are all located on chromosome 5. The UniprotKB primary accession numbers for rat C1q are: C1q A chain (P31720), C1q B chain (P31721), and C1q C chain (P31722).Precautions/Toxicity/HazardsThis protein is purified from animal plasma/serum and therefore precautions appropriate for handling any animal blood-derived product must be used.ReferencesMedgyesi, G.A et., Miklos, K., Kulics, J., Fust, G., and Gergely, J. Bazin, H. (1981). Classes and subclasses of rat antibodies: reaction with the antigen and interaction of the complex with the complement system. Immunology 43, 171-176.Redpath, S., Michaelsen, T., Sandlie, I. and Clark, M. R. (1998). Activation of complement by human IgG1 and human IgG3 antibodies against the human leucocyte antigen CD52. Immunology 93, 595–600.Veerhuis, R., Van Es, L.A. and Daha, M.R. (1985). In vivo degradation of rat C1q induced by intravenous injection of soluble IgG aggregates. Immunology 54, 801-810.Wing, M.G., Seilly, D. J., Bridgman, D.J. and Harrison, R.A. (1993). Rapid isolation and biochemical characterization of rat C1 and C1q. Molecular Immunology 30, 433-440... Read More | Inquire | Reverse transcriptases are enzymes encoded in retroviruses viral genome. The enzyme is responsible for transcription of the viral RNA to produce a dsDNA that can be inserted into the host genome.Reverse transcriptases are multifunctional enzymes. These enzymes exhibit an RNA and DNA directed Reverse transcriptases are enzymes encoded in retroviruses viral genome. The enzyme is responsible for transcription of the viral RNA to produce a dsDNA that can be inserted into the host genome.Reverse transcriptases are multifunctional enzymes. These enzymes exhibit an RNA and DNA directed polymerase activity. In addition reverse transcriptases catalyze the degradation of RNA in an RNA-DNA hybrid. The exonucleolytic activity proceeds in a 5' ---> 3' direction. The RNA or DNA directed activity requires a template (RNA or DNA) and a primer. The following is a schematic illustration of the reaction:Unit definition: One unit incorporates 1 nanomole of tritiated dTMP into acid insoluble productsusing poly(A)•oligo(dT) 12-18 as the template-primer in 20 minutes at 37° C.ApplicationsHIV reverse transcriptase is used for research on the AIDS primer. However it can be substituted for AMV reverse transcriptase, which is mainly used to transcribe mRNA into double stranded cDNA, that can be inserted into prokaryotic vectors. The enzyme can also be used with either single stranded DNA or RNA templates to make probes for use in hybridization experiments. It can be used for labeling the termini of DNA fragments with protruding 5' termini. The enzyme can also be used to sequence DNAs by the dideoxy chain termination method of Sanger when the Klenow fragment of E. coli DNA polymerase I, or the T7 DNA polymerase yield unsatisfactory results.Reagents0.05 M Tris, pH 8.3, containing 0.008 M MgCl21 mg/ml polyadenylic acid in water (poly A)DNA primer:Oligo d(T)12-181 µ mole dTTP/mL stock solution[methyl-3H]-Thymidine 5'-triphosphate (3H-dTTP)dTTP-3H-dTTP working mix: Add 1-2 µL 3H-dTTP per mL of 100 nmol/mL dTTP in order to obtain 1 to 1.5 x 105 cpm/mL1% bovine serum albumin10% perchloric acid1% perchloric acidBuffer substrate reaction mixture: Prepare fresh, immediately before use:For each 1mL of reaction mixture required mix:0.7 mL Tris/HCl, pH 8.3, 0.008M MgCl20.3 mL 1 mg/mL poly(A) RNA template0.005 mL 0.02 mg/mL oligo d(T)12-18 DNA primer0.02mL 1% BSAEnzymedilute as needed wtih 0.05M Tris/HCl, pH 8.3, 0.008M MgCl2 containing 0.1 mg/mL (1%) BSAProcedurePipette into each tube as follows:Buffer substrate mix：0.1 mLdTTP-3H3-dTTP：0.1 mLEnzyme：5-10 µLIncubate 20 minutes at 37° C. Stop reaction by adding 1 ml 10% cold perchloric acid. Filter through 0.2µ manifold filters used with Millipore vacuum manifold. Wash four times using 2mL 1% cold perchloric acid/wash. Transfer filter to scintillation vials. Add 2mL Cellosolve (or 2-methoxyethanol) to dissolve filter. Filters become opaque upon addition of Cellosolve. Make sure filters are dissolved before proceeding. Add 10mL scintillation cocktail and count.Calculation... Read More |