||Recombinant Human Cytokeratin 19 produced inE.Coliis a single, non-glycosylated polypeptide chain having a molecular mass of 44,098 Dalton. The CTK-19 is purified by proprietary chromatographic techniques.
||CTK-19 is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic cytokeratin is not paired with a basic cytokeratin in epithelial cells. It is specifically expressed in the periderm, the transiently superficial layer that envelopes the developing epidermis. The type I cytokeratins are clustered in a region of chromosome 17q12-q21.
||Sterile Filtered White lyophilized (freeze-dried) powder.
||The protein (1mg/ml) was lyophilized after from a sterile solution containing 30mM Tris-HCL pH-8, 9.5M urea, 2mM EDTA and 10mM methylammonium chloride.
||It is recommended to reconstitute the lyophilized CTK-19 in sterile 18MΩ-cm H2O not less than 100µg/ml, which can then be further diluted to other aqueous solutions.
||Lyophilized CTK-19 although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution CTK-19 should be stored at 4°C between 2-7 days and for future use below -18°C. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Please prevent freeze-thaw cycles.
||Greater than 95.0% as determined by: (a) Analysis by RP-HPLC. (b) Analysis by SDS-PAGE.
|Reconstitution To Filaments:
||Performed by mixing equimolar amounts of cytokeratins of type I and type II at concentrations of approx. 0.5 mg/ml, both dissolved in 9.5 M urea buffer (see above). Protofilaments and filament complexes are obtained by dialyzing the resulting polypeptide solution stepwise to a concentration of 4 M urea and then to low salt condition (50 mM NaCI, 2 mM dithiothreitol, 10 mM Tris-HCI, pH 7.4). For immunization purposes, the solution can be further dialyzed against PBS.