| Description | Protease S. aureus, V8 (endoproteinase-Glu-C) specifically cleaves peptide bonds on the COOH-terminal side of either aspartic or glutamic acids (Drapeau et al. 1972). Houmard and Drapeau (1972) report that in the presence of ammonium buffers the enzyme specificity can be limited to glutamoyl bonds. Protease S. aureus, V8 (endoproteinase-Glu-C) specifically cleaves peptide bonds on the COOH-terminal side of either aspartic or glutamic acids (Drapeau et al. 1972). Houmard and Drapeau (1972) report that in the presence of ammonium buffers the enzyme specificity can be limited to glutamoyl bonds. Its rather unique specificity, which can be considered as opposite to that of trypsin, makes it a useful tool for protein chemistry and peptide mapping studies (Cleveland et al. 1977) and (Hall et al. 1978).Characteristics of Protease from S. aureus, V8:Characteristics of Protease, Staph aureus (Endoproteinase Glu-C)Molecular Weight27,000 (Drapeau 1978).Optimal pH4.0 and 7.8 with hemoglobin substrate. (Drapeau et al. 1972).Extinction Coefficientextinction coefficient = 4.26 (Houmard 1976).InhibitorsDiisopropyl fluorophosphate (DFP) and monovalent anions such as F-, Cl-, Br-, CH3COO-, and NO3- (Houmard 1976).MethodEnzyme activity is determined by the casein digestion assay described by Drapeau (1976). Since substrate grade caseins can vary from lot to lot and according to the manner produced, the standardization of casein digestion assays has been difficult to achieve. The use of a reference enzyme preparation is suggested. One unit is that amount of enzyme which releases acid soluble fragments equivalent to 0.001 A280 per minute at 37°C and pH 7.8 under the specified conditions.Reagents1% Casein in 0.05 M Tris⋅PO4 buffer, pH 7.8. (Dissolve 1 gram "Hammersten" casein in 50 ml 0.01 N NaOH with gentle heating and stirring. Add 40 ml reagent grade water and 5.0 ml 1.0 M Tris. Adjust pH to 7.8 with H3PO4 and q.s. to 100 ml.)10% Trichloroacetic acid (TCA)EnzymeDissolve at 1 mg/ml in reagent grade water.ProcedureEquilibrate a series of tubes with 5.0 ml of 1% casein at 37°C for 5 minutes. At zero time add 10 ul or 20 ul of enzyme. Mix. Include a reagent blank. Exactly ten minutes after adding sample, stop reaction by adding 5.0 ml TCA. Mix. Allow tubes to stand ten minutes and then filter. Read A280 of the filtrate.Calculation... Read More | Inquire | Purity:>95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： This protein is a cell adhesion molecule involved in neuron-neuron adhesion, neurite fasciculation, outgrowth of neurites, etc | Purity>97% SDS-PAGE.FunctionReceptor for interleukin-2 | Purity: >95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： Mesothelin (MSLN), also known as CAK1 and ERC, is a glycosylated cell-surface antigen present on normal mesothelial cells and over-expressed in several human tumors. The mesothelin gene encodes a ~70 kDa Purity: >95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： Mesothelin (MSLN), also known as CAK1 and ERC, is a glycosylated cell-surface antigen present on normal mesothelial cells and over-expressed in several human tumors. The mesothelin gene encodes a ~70 kDa precursor protein that is cleaved at a dibasic proteolytic site into a 40 kDa membrane-bound protein termed MSLN and a 31 kDa shed fragment called megakaryocyte-potentiating factor (MPF) that is released from the cell. Cleaved, human MSLN remains attached to the cell surface via a GPI linkage and shares 58% amino acid sequence identity with mouse and rat MSLN. In human, alternate splicing generates additional MSLN isoforms that have either an eight amino acid insertion following Ser408 or a substituted C‑terminal region with no GPI anchor. Mesothelin is normally expressed on mesothelial cells in the pleura, pericardium, and peritoneum as well as in the developing and postnatal pancreas. It is up‑regulated in mesotheliomas and a range of carcinomas and adenomas. Mesothelin promotes tumor cell proliferation, migration, anchorage-independent growth, and tumor progression. It is co‑expressed with the tumor antigen CA125/MUC16 on advanced ovarian adenocarcinomas and interacts with this molecule to support cell adhesion. A soluble form of Mesothelin is released from tumor cells into the serum or tissue effusions... Read More |