BD-4-2

E.coli

Defensin beta4，Beta-defensin 4，BD-4，Defensin, beta 4

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.

Approximately 4.4 kDa.

QSINNPITCL TKGGVCWGPC TGGFRQIGTC GLPRVRCCKK K

Sterile Filtered White lyophilized (freeze-dried) powder.

> 95 % by SDS-PAGE and HPLC analyses.

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.

< 1.0 EU per 1μg of the protein

Lyophilized from a 0.2 µm filtered concentrated solution in 10 mM PB, pH 7.4, 500 mM NaCl.