| Description | Clostripain (Endoproteinase-Arg-C) is a two chain proteinase associated with collagenase and isolated from Clostridium histolyticum. It is highly specific for the carboxyl peptide bond of arginine. Clostripain has a sulfhydryl requirement; it is activated by dithiothreitol, cysteine, or other Clostripain (Endoproteinase-Arg-C) is a two chain proteinase associated with collagenase and isolated from Clostridium histolyticum. It is highly specific for the carboxyl peptide bond of arginine. Clostripain has a sulfhydryl requirement; it is activated by dithiothreitol, cysteine, or other sulfhydryl containing reagents. The presence of calcium ions is essential. The enzyme is inhibited by oxidizing agents and sulfhydryl reactants and by Co²⁺, Cu²⁺, Cd²⁺, and heavy metal ions. Citrate, borate, and Tris anions are less inhibitory.Clostripain is a cysteine-activated protease found, along with collagenase and other proteases, in culture filtrates of Clostridium histolyticum. It is unique in its specificity for the carboxyl peptide bond of arginine and its dependence on thiol and calcium ions.SpecificityClostripain selectively hydrolyzes arginyl bonds and lysyl bonds at a lower rate. It can also act as a transpeptidase with maximal activity at pH 7.6-9.0.CompositionClostripain is a heterodimer. The mature chain is composed of 526 residues. The two chains are held together by strong noncovalent forces. The catalytic sulfhydryl residue of the active site is believed to be Cys41 (heavy chain residue). The precursor contains a 27 amino acid putative signal peptide, a 23 amino acid propeptide, a 131 amino acid light chain subunit, a 9 amino acid linker peptide, and a 336 amino acid heavy chain subunit.Molecular CharacteristicsBoth the heavy and light chains are encoded by a single gene with a 1581 nucleotide open reading frame (ORF). Upon expression of the gene, the entire ORF (the signal region, proregion, and 9 amino acid peptide linker) is transcribed. Postranslational processing produces the heterodimeric active enzyme.ApplicationsPeptide mappingSequence analysisCell isolationHydrolysis/condensation of amide bondsPeptide synthesisCharacteristicsMolecular Weight: 53.0 kDa (Theoretical); Light chain: 12.5 kDa, Heavy chain: 45 kDaOptimal pH: 7.4-7.8 (activity against a-benzoyl-arginine ethyl ester)Isoelectric point: 4.8-4.9Extinction Coefficient: 87,890 cm⁻¹ M⁻¹ (Theoretical); E1%,280= 16.57 (Theoretical)Active Site Residues: Cysteine (C41, heavy chain)Activators: Sulfhydryl requirement: dithiothreitol, cysteine, or other reducing agents, Calcium ion is essential, Reducing agentsInhibitors: EDTA, Oxidizing agents, Sulfhydryl reagents (such as TLCK), Co2+, Cu2+, Cd2+, and heavy metal ions, Citrate, borate and Tris anions partially inhibitAssayMethodThe reaction velocity is measured as an increase in absorbance at 253 nm resulting from the hydrolysis of N-benzoyl-L-arginine ethyl ester. One unit hydrolyzes one micromole of BAEE per minute at 25°C and pH 7.6 under the conditions specified.Reagents0.075 M Sodium phosphate buffer, pH 7.67.5 mM Dithiothreitol (DTT)0.75 mM N-Benzoyl-L-arginine ethyl ester (BAEE)1.0 mM Calcium acetate containing 2.5 mM dithiothreitol (activation solution)EnzymeDissolve or dilute the enzyme at a concentration of 1 mg/ml in water. Immediately prior to assay, dilute the enzyme further in 1.0 mM Calcium acetate containing 2.5 mM dithiothreitol to a concentration of 0.2-0.8 units/ml.ProcedureAdjust spectrophotometer to 253 nm and 25°C.Pipette into each cuvette as follows:0.075 M phosphate buffer, pH 7.61.0 ml7.5 mM DTT1.0 ml0.75 mM BAEE1.0 mlIncubate in spectrophotometer for 3-5 minutes to achieve temperature equilibrium and establish blank rate, if any. At zero time, add 0.1 ml of appropriately diluted enzyme and record A253 for 4-5 minutes. Determine ΔA253/minute from the linear portion of the curve. Note: The reaction appears to be most linear with respect to enzyme concentration when ΔA253/min is between 0.007 and 0.030.Calculationwhere 1150 is the extinction coefficient of BAEE at 253 nm... Read More | Inquire | Purified pectinase is a multi-component preparation highly effective in depolymerizing plant pectins with varying degrees of esterification. The product contains substantial hemicellulase, cellulase, pectinesterase and xylanase activities which together with pectin lyase and polygalacturonase work Purified pectinase is a multi-component preparation highly effective in depolymerizing plant pectins with varying degrees of esterification. The product contains substantial hemicellulase, cellulase, pectinesterase and xylanase activities which together with pectin lyase and polygalacturonase work synergistically to digest plant cell wall tissues. When used with Worthington purified cellulase, purified pectinase has been found to be highly successful for generating good yields of viable protoplasts in several plant systems, e.g., corn, soybean, red beet, sunflower, tomato and citrus. In general, a concentration range of 0.1% to 0.5% pectinase (with accompanying 0.5% to 1.5% cellulase) used at 24°C to 37°C for periods of 1 to 16 hours will yield good results... Read More | Purity:>90%, by SDS-PAGE visualized with Coomassie® Blue Staining.Description：IL12 is a cytokine that acts on T and natural killer cells, and has a broad array of biological activities. It is a disulfide-linked heterodimer composed of the 40 kD cytokine receptor like subunit and a 35 Purity:>90%, by SDS-PAGE visualized with Coomassie® Blue Staining.Description：IL12 is a cytokine that acts on T and natural killer cells, and has a broad array of biological activities. It is a disulfide-linked heterodimer composed of the 40 kD cytokine receptor like subunit and a 35 kD subunit. This cytokine is expressed by activated macrophages that serve as an essential inducer of Th1 cells development. IL12 has been found to be important for sustaining a sufficient number of memory/effector Th1 cells to mediate long-term protection to an intracellular pathogen. Recombinant human IL12 protein, fused to His-tag at C-terminus, was expressed in insect cells using baculovirus expression system and purified by using conventional chromatography techniques... Read More | 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 |