Description
Defensins are a large family of peptides of which two groups exist in mammals: alpha defensins and beta defensins, which are distinguishable by the spacing and connectivity of the conserved cysteine residues within the mature peptides.It is thought that defensins function in the eradication of pathogens from the host system by inserting themselves into the bacterial membrane under the influence of membrane potential, forming channels which lead to leakage of cytoplasmic molecules and cell death. Unlike hBD-1, this second peptide, human beta-defensin-2 (hBD-2), is regulated at a transcriptional level in response to contact with microorganisms, and is highly eåective in killing the gram negative bacteria Its expression is also upregulated by the cytokine tumor necrosis factor-alpha