Defensins (alpha and beta) are cationic peptides with a broad spectrum of antimicrobial activity that comprise an important arm of the innate immune system. The α-defensins are distinguished from the β-defensins by the pairing of their three disulfide bonds. To date, six human β-defensins have been identified; BD-1, BD-2, BD-3, BD-4, BD-5 and BD-6. β-defensins are expressed on some leukocytes and at epithelial surfaces. In addition to their direct antimicrobial activities, they can act as chemoattractants towards immature dendritic cells and memory T cells. The β-defensin proteins are expressed as the C-terminal portion of precursors, and are released by proteolytic cleavage of a signal sequence and, in some cases, a propeptide sequence. β-defensins contain a six-cysteine motif that forms three intra-molecular disulfide bonds. BD-4 is expressed in the testes, stomach, uterus, neutrophils, thyroid, lungs and kidneys. Product Properties Synonyms Defensin beta4，Beta-defensin 4，BD-4，Defensin, beta 4 Accession O88514 GeneID 64389 Source E.coli-derived rat Beta-defensin 4 protein, Gln23-Lys63 Molecular Weight Approximately 4.4 kDa. AA Sequence QSINNPITCL TKGGVCWGPC TGGFRQIGTC GLPRVRCCKK K Tag None Physical Appearance Sterile Filtered White lyophilized (freeze-dried) powder. Purity > 95 % by SDS-PAGE and HPLC analyses. Biological Activity Fully biologically active when compared to standard. The biologically active determined by a chemotaxis bioassay using human monocytes is in a concentration range of 0.1-100.0 ng/ml. Endotoxin < 1.0 EU per 1μg of the protein by the LAL method. Formulation Lyophilized from a 0.2 µm filtered concentrated solution in 10 mM PB, pH 7.4, 500 mM NaCl. Reconstitution We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1 % BSA to a concentration of 0.1-1.0 mg/ml. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriate buffered solutions. Shipping and Storage The products are shipped with ice pack and can be stored at -20℃ to -80℃ for 1 year. Recommend to aliquot the protein into smaller quantities when first used and avoid repeated freeze-thaw cycles. Cautions 1. Avoid repeated freeze-thaw cycles. 2. For your safety and health, please wear lab coats and disposable gloves for operation. 3. For research use only!
