| Description | Inquire | Inquire | Carboxypeptidase B catalyzes hydrolysis of the basic amino acids lysine, arginine and histidine from theC-terminal end of polypeptides. The molecular weight is 34,500 daltons, the pH optimum is 8.0, and pI is 6.0.Carboxypeptidase B is competitively inhibited by arginine and lysine. The enzyme is Carboxypeptidase B catalyzes hydrolysis of the basic amino acids lysine, arginine and histidine from theC-terminal end of polypeptides. The molecular weight is 34,500 daltons, the pH optimum is 8.0, and pI is 6.0.Carboxypeptidase B is competitively inhibited by arginine and lysine. The enzyme is also inhibited by metal chelating agents, e.g., EDTA. Recombinant Carboxypeptidase B (EC 3.4.17.2) is expressed in E.Coli and purified by high pressure liquid chromatography. There is no trace of other enzyme (such as carboxypeptidase A and chymotrypsin) activity. No protease inhibitors such as PMSF are present in the preparation.Animal origin free:eliminate the risk of virus presence, or of any other potential adventitious agents found in animal-derived carboxypeptitase B.Stability:A sterile recombinant carboxypeptidase B lyophilized eliminates the risk of contamination and decreases the chances of activity loss in the process of transport and storage. High purity:1) Recombinant carboxypeptidase B provides increased specific activity and eliminates contaminating protease activities found in extracted enzymes with lower purity level. 2) No other contaminating proteases such as chymotrypsin and carboxypeptidase A. 3）Less than 10ppm of recombinant trypsin... 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 | 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 |