| 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 | Sequence:Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-His-His-Gln-Lys-Leu-Val-Phe-Phe-Ala-Glu-Asp-Val-Gly-Ser-Asn-Lys-Gly-Ala-Ile-Ile-Gly-Leu-Met-Val-Gly-Gly-Val-Val-Ile-AlaBiochemical mechanism:Amyloid protein β Protein segment 1-42 (A β 1-42) It has antioxidant and neuroprotective Sequence:Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-His-His-Gln-Lys-Leu-Val-Phe-Phe-Ala-Glu-Asp-Val-Gly-Ser-Asn-Lys-Gly-Ala-Ile-Ile-Gly-Leu-Met-Val-Gly-Gly-Val-Val-Ile-AlaBiochemical mechanism:Amyloid protein β Protein segment 1-42 (A β 1-42) It has antioxidant and neuroprotective properties. Amyloid protein β Protein accumulation is associated with Alzheimer's disease (AD) and Down syndrome. A β 1-42 regulates cholesterol transport and acts as a transcription factor. It may also have anti-inflammatory and antimicrobial effects.Application:Amyloid protein is found in the brain of patients with Alzheimer's disease and Down syndrome β- The main segment of the protein.Amyloid protein β Protein fragments 1-42 have been used to:1. A β Preparation of 1-42 oligomer2. Western blot analysis3. Immunomagnetic Reduction (IMR) Plasma A β 42 Detected interference test4. Study the effect of resveratrol on A β 1-42 induced impairment of spatial learning, memory and synaptic plasticity5. Study A β Role in epithelial cell culture... Read More | DescriptionApolipoprotein E (ApoE) is present in the brain and is mainly produced by astrocytes. It is a 299 amino acid glycoprotein of 34kDa. It is present in all classes of lipoproteins except LDL (low-density lipoprotein). APOE gene has three alleles, such as APOE ε3, APOE ε4and APOE &#DescriptionApolipoprotein E (ApoE) is present in the brain and is mainly produced by astrocytes. It is a 299 amino acid glycoprotein of 34kDa. It is present in all classes of lipoproteins except LDL (low-density lipoprotein). APOE gene has three alleles, such as APOE ε3, APOE ε4and APOE ε2. It is located on human chromosome 19q13.Preparation instructionsFormLyophillized from a 0.2 µm filtered solution in 20 mM sodium phosphate, pH 7.8.Principle... Read More | Purity: >90%, by SDS-PAGE visualized with Coomassie® Blue Staining.Description：CNN1 is a member of the calponin family. CNN1 is a thin filament-associated protein which is involved in the regulation and modulation of smooth muscle contraction. CNN1 is able to bind to actin, calmodulinPurity: >90%, by SDS-PAGE visualized with Coomassie® Blue Staining.Description：CNN1 is a member of the calponin family. CNN1 is a thin filament-associated protein which is involved in the regulation and modulation of smooth muscle contraction. CNN1 is able to bind to actin, calmodulin, troponin C and tropomyosin. Prevention of actomyosin Mg-ATPase activity is a result of interaction between calponin and actin... Read More | Purity: >90%, by SDS-PAGE visualized with Coomassie® Blue Staining. Function：Actin cross-linking/gelling protein (By similarity). Involved in calcium interactions and contractile properties of the cell that may contribute to replicative senescence |