| Description | Inquire | 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 | TEV Protease is the 241 amino acid (aa), 27 kDa catalytic domain of the nuclear inclusion a (NIa) protein encoded by the potyvirus, tobacco etch virus (TEV). It may be used in biotechnology to cleave affinity tags from recombinant proteins, either co-translationally orin vitrofollowing purification.TEV Protease is the 241 amino acid (aa), 27 kDa catalytic domain of the nuclear inclusion a (NIa) protein encoded by the potyvirus, tobacco etch virus (TEV). It may be used in biotechnology to cleave affinity tags from recombinant proteins, either co-translationally orin vitrofollowing purification. Its high specificity and activity at a wide range of pH and ionic strength make TEV Protease more versatile than many other proteases used for the same purpose. Unlike factor Xa, enteropeptidase or thrombin, TEV Protease has not been found to cleave at unintended sites, even when present at a high concentration. TEV Protease is a 3C-type protease that cleaves substrates with a consensus sequence of ENLYFQG. Cleavage occurs between Q and G. Since the final aa remains on the cleaved protein where it could potentially affect structure or function, substitution of a variety of aa have been tested. In order of efficiency, S, A, M, Y, D, N, E, K or L may be effectively used in place of G. Several of the remaining aa may also vary, giving a final consensus sequence of ExxYF(M)Q(E)/G(S, A or others) where aa in parenthesis are alternatives and x is any aa. The autocatalytic site of NIa at S2256 has been mutated to an N for improved stability of the protease.Tobacco Etch Virus Protease is a highly site-specific cysteine protease that is found in the tags from fusion proteins. The optimal temperature for cleavage is 30°C. It is recommended that the cleavage for each fusion protein be optimized by varying the amount of recombinant viral TEV protease, reaction time, or incubation temperature. It can be removed by Ni2+ affinity resin... Read More | Purity: >90%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description: Major histocompatibility complex, class II, DR alpha (HLA-DRA) belongs to the MHC class II family. HLA-DRA binds peptides derived from antigens which access the endocytic route of antigen presenting cells (APC) Purity: >90%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description: Major histocompatibility complex, class II, DR alpha (HLA-DRA) belongs to the MHC class II family. HLA-DRA binds peptides derived from antigens which access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for identification by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mainly by degradation of proteins which access the endocytic route, where they are processed by lysosomal proteases and other hydrolases... Read More | BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L,BackgroundStreptavidin is a tetrameric bacterial protein isolated from Streptomyces avidinii providing 4 high-affinity biotin binding sites. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin. With a dissociation constant on the order of ≈10⁻¹⁴ mol/L, the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature. Unlike egg-white avidin, which has a net positive charge at neutral pH and contains about 7% carbohydrate, streptavidin has almost no net charge at neutral pH, does not contain carbohydrate, and exhibits lower non-specific background. Streptavidin conjugates are widely used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids and other molecules. This FITC-streptavidin conjugate was prepared by highly purified Streptavidin and free FITC was removed. Streptavidin (FITC) is a useful second-step reagent for the indirect immunofluorescent staining of cells in combination with biotinylated primary antibodies for flow cytometric analysis. Excitation at 488nm light leads to a fluorescence emission maximum of 520 nm.Recommended Usage：Every lot of Streptavidin-FITC is tested by flow cytometry using biotinylated primary antibodies. From this testing it is recommended that between 0.02 and 0.25 µg of streptavidin be used per 106 cells in a 100 µl staining volume... Read More |