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 the function of defensins in the eradication of pathogens from the host system is to insert themselves into the bacterial membrane under the influence of membrane potential, in doing so forms 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 effective in killing the gram negative bacteria. Its expression is also upregulated by the cytokine tumor necrosis factor-alpha