BD-4, human recombinant

Defensins are cationic peptides with a large spectrum of antimicrobial activity that comprise an important arm of the innate immune system. The Alpha defensins are differentiated from the Beta-defensins by the pairing of their 3 disulfide bonds. Four human Beta-defensins have been identified to date; BD-1, BD-2, BD-3 and BD-4. Beta-defensins are expressed on some leukocytes and at epithelial surfaces. In addition to their direct antimicrobial activities, they are chemoattractant towards immature dendritic cells and memory T cells. Beta-defensin proteins are expressed as the C-terminal portion of precursors and are released by proteolytic cleavage of a signal sequence (for BD-1 a propeptide region). Beta-defensins contain a six-cysteine motif that forms three intra-molecular disulfide bonds. Beta Defensin-4 Human Recombinant produced in E.Coli is a single, non-glycosylated polypeptide chain containing 50 amino acids. The BD-4 is purified by proprietary chromatographic techniques.