重組大鼠β-防御素4蛋白

Synonyms	Defensin beta4
Species	Rat
Accession	O88514
GeneID	64389
Source	Escherichia coli.
Molecular Weight	重組大鼠β-防御素4蛋白Approximately 4.4 kDa, a single non-glycosylated polypeptide chain containing 41 amino acids.
Quantity	5μg/20μg/1000μg
AA Sequence	QSINNPITCL TKGGVCWGPC TGGFRQIGTC GLPRVRCCKK K
Purity	> 95 % by SDS-PAGE and HPLC analyses.
Biological Activity	重組大鼠β-防御素4蛋白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.
Physical Appearance	Sterile Filtered White lyophilized (freeze-dried) powder.
Formulation	Lyophilized from a 0.2 μm filtered concentrated solution in 10 mM PB, pH 7.4, 500 mM NaCl.
Endotoxin	重組大鼠β-防御素4蛋白Less than 1 EU/μg of rRtBD-4 as determined by LAL method.
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.
Storage	This lyophilized preparation is stable at 2-8 °C, but should be kept at -20 °C for long term storage, preferably desiccated. Upon reconstitution, the preparation is stable for up to one week at 2-8 °C. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20 °C to -70 °C. Avoid repeated freeze/thaw cycles.
重組大鼠β-防御素4蛋白
SDS-PAGE
Reference	1. Musumeci G, Carnazza ML, Loreto C, et al. 2012. Acta Histochem, 114: 805-12. 2. Biragyn A, Ruffini PA, Leifer CA, et al. 2002. Science, 298: 1025-9. 3. Otte JM, Neumann HM, Brand S, et al. 2009. Eur J Clin Invest, 39: 126-38.
Background	Defensins (alpha and beta) are cationic peptides with antimicrobial activity against Gram-negative and Gram-positive bacteria, fungi, and enveloped viruses. They are 2-6 kDa proteins and take important roles in innate immune system. On the basis of their size and pattern of disulfide bonding, mammalian defensins are classified into alpha, beta and theta categories. β-Defensins are expressed on some leukocytes and at epithelial surfaces. They contain a six-cysteine motif that forms three intra-molecular disulfide bonds. Because β-defensins are cationic peptides, they can therefore interact with the membrane of invading microbes, which are negative due to lipopolysaccharides (LPS) and lipoteichoic acid (LTA) found in the cell membrane. Especially, they have higher affinity to the binding site compared to Ca2+ and Mg2+ ions. Furthermore, they can affect the stability of the membrane. Additionally, they are not only have the ability to strengthen the innate immune system but can also enhance the adaptive immune system by chemotaxis of monocytes, T-lymphocytes, dendritic cells and mast cells to the infection site.