| 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 | A general purpose purified albumin, suitable for Westerns, enzyme systems and as a protein supplement | Arachis hypogaea lectin or Peanut Agglutinin (PNA) is isolated from peanuts and purified by affinity chromatography. The lectin has a molecular weight of 110 kDa and consists of four identical subunits of approximately 27 kDa each. PNA is a carbohydrate-free protein that displays specificity towardsArachis hypogaea lectin or Peanut Agglutinin (PNA) is isolated from peanuts and purified by affinity chromatography. The lectin has a molecular weight of 110 kDa and consists of four identical subunits of approximately 27 kDa each. PNA is a carbohydrate-free protein that displays specificity towards ?-D-Gal(1-3)-D-galNAc. It has potent anti-T activity and can be used to distinguish between human lymphocyte subsets. PNA has been used in tumour tissue determination for transitional mucosa malignancies. The lectin also agglutinates neuraminidase-treated human erythrocytes at < 0.1 µg/ml after trypsin treatment of cells and its activity is inhibited by lactose and galactose. PNA lectin is provided as a white to light yellow lyophilized powder from a buffer containing 10 mM NH4HCO3. The purity is determined by SDS-PAGE, which generates one band at 25-27 kDa.● Ultrapure quality ● Strong anti-T activity ● Sugar specificity: ?-D-Gal-(1-3)-D-GalNAc ● Agglutinates rabbit erythrocytes at < 0.1 µg/ml after trypsin treatment of the cells ● Lyophilized powderProbe in histochemistry and immuno-histochemistry;Human erythrocyte/lymphocyte studies... Read More | Protein Purity≥85% by SDS PAGEExtinction CoeffA280 nm = 10.16 at 1.0 mg/ml for pure C3Molecular Weight187,000 Da (2 chains)General DescriptionRat C3 is purified from pooled normal rat serum. C3 is central to the activation of all three pathways of complement activation (Law, S.K.A. and Reid, KProtein Purity≥85% by SDS PAGEExtinction CoeffA280 nm = 10.16 at 1.0 mg/ml for pure C3Molecular Weight187,000 Da (2 chains)General DescriptionRat C3 is purified from pooled normal rat serum. C3 is central to the activation of all three pathways of complement activation (Law, S.K.A. and Reid, K.B.M. (1995)). Initiation of each pathway generates proteolytic enzyme complexes (C3 convertases) which are bound to the target surface. These enzymes cleave a peptide bond in C3 releasing the anaphylatoxin C3a and activating C3b. For a brief time (~60 µs) this nascent C3b is capable of reacting with and covalently coupling to hydroxyl groups on the target surface. Carbohydrates are the favored target, but protein hydroxyls and amino groups also react. This process of tagging the target surface with C3b is called opsonization. The reactive site in nascent C3b is a thioester (Tack B.J., et al. (1980); Pangburn M.K. and MüllerEberhard H.J. (1980)) and C3b is linked to the target through a covalent ester bond (an amide bond is formed if C3b is attached to amino groups). Most of the C3 activated during complement activation never attaches to the surface because its thioester reacts with water forming fluid phase C3b which is rapidly inactivated by factors H and I forming iC3b. Surface-bound C3b is necessary in all three pathways for efficient activation of C5 and formation of C5b-9 complexes that lyse the target cell membrane. Surface-bound C3b and its breakdown products iC3b and C3d are recognized by numerous receptors on lymphoid and phagocytic cells which use the C3b ligand to stimulate antigen presentation to cells of the adaptive immune system. The end result is an expansion of target-specific B-cell and T-cell populations.Physical Characteristics & StructureThe calculated molecular weight of rat C3 based on its amino acid sequence is 184,111daltons (without the signal peptide) and is similar to that of human C3 (185,000 daltons).The molecular weight of rat C3 as determined by SDS/polyacrylamide gel electrophoresis has been reported by Daha, M.R. et al., (1979) to be 187,000 daltons composed of two disulfide linked chains, alpha chain (123,000 daltons) and beta chain (76,000 daltons). The extinction coefficient of rat C3 (E1%/280nm = 10.16) is calculated based on its amino acid sequence using ProtParam and assumes all pairs of Cys residues form cystines (i.e. a pair of cysteine molecules are joined by a disulfide bond). The theoretical pI of rat C3 is 6.12. The normal plasma concentration of C3 inWistar rats has been reported to be 0.581mg/ml (Daha, M.R. et al., (1979)).FunctionThe biological functions of C3 are described above in the General Description section.GeneticsRat C3 chromosome location 9. The NCBI Gene ID number for rat C3 is 24232 and UniProt accession number is P01026.Precautions/Toxicity/HazardsThis protein is purified from animal plasma/serum and therefore precautions appropriate for handling any animal blood-derived product must be used.ReferencesLaw, S.K.A. and Reid, K.B.M. (1995) Complement 2nd Edition (ISBN 0199633568) Oxford University Press, Oxford.Tack BF, Harrison RA, Janatova J, Thomas ML, Prahl JW. (1980) Evidence for presence of an internal thiolester bond in third component of human complement. Proc Natl Acad Sci U S A. 77:5764-8.Pangburn M.K. and Müller-Eberhard H.J. (1980) Relation of putative thioester bond in C3 to activation of the alternative pathway and the binding of C3b to biological targets of complement. J Exp Med. 152:1102-14.Daha MR, Stuffers-Heiman M, Kijlstra A and Van ES LA. (1979) Isolation and characterization of the third component of rat complement. Immunology 36:63-70... Read More | Acid phosphatase is an esterase with broad activity at an optimal pH below 7.0. There are three isozymes, EI, EII, and EIII of similar molecular weight (55 kDa± 5 kDa). Their optimum pH's are 5.5, 4.5, and 4.0 respectively. Acid phosphatase activity was observed by Teller Aladdin Library Acid phosphatase is an esterase with broad activity at an optimal pH below 7.0. There are three isozymes, EI, EII, and EIII of similar molecular weight (55 kDa± 5 kDa). Their optimum pH's are 5.5, 4.5, and 4.0 respectively. Acid phosphatase activity was observed by Teller Aladdin Library Archives in 1954 in preparations of a wheat germ lipase described by Singer JBC, 174, 11, in 1948. Equivalent commercial preparations have been distributed labeled as lipase and acid phosphatase thus generating some confusion. Subsequent work has confirmed that the non-specific esterase activity of the wheat germ preparation may be measured both as lipase (triacetin as substrate) and phosphatase. The enzyme assay is based on the work of Brandenberger and Hanson (Helv. Chim. Acta, 36, 900, 1953) and Hofstee ( Arch. Biochem. Biophys., 51, 239, 1954).Acid phosphatase (APase) non-specifically catalyzes the hydrolysis of monoesters and anhydrides of phosphoric acid to produce inorganic phosphate. It is used to study the production, transport, and recycling of phosphate and the metabolic and energy transduction processes of the cell.Characteristics of Acid Phosphatase from Wheat Germ:Molecular weight: 55,000 ± 5,000 (Verjee 1969).Composition: Three isozymes of closely similar molecular weights have been reported by Verjee (1969): EI, EII, and EIII. See also Brouillard and Ouellet (1965).Optimal pH: EI - 5.5, EII - 4.5, and EIII - 4.0. (Verjee 1969).Specificity: The enzyme has a broad esterase activity. See Joyce and Grisolia (1960). It shows highest activity for pyrophosphate.Inhibitors: Fluoride, molybdate and orthophosphate (Verjee 1969)... Read More |