Molecular and functional characterization of bovine b-defensin-1

AbstractWe report the biochemical and functional properties of a novel bovine b-defensin (bBD-1). Cloned from bovine mammarypapillaryductepithelia,thebBD-1cDNApredictsa69aminoacidpropeptidethatismuchmoresimilartohumanb-defensin-1(hBD-1)thantootherbovinedefensins.ThebBD-1genecontainstwoexonsandone8.5 kbintron.UsingRT-PCR,wedetectedthe bBD-1 transcript in the teat mucosa, kidney, vagina, ovary, oviduct, and colon. A synthetic bBD-1 peptide demonstratespotent antibacterial activity against Escherichia coli. The widespread expression of bBD-1 mRNA indicates that bBD-1 mayplay an important role in the bovine host defense against infections.# 2006 Elsevier B.V. All rights reserved. Keywords: Antimicrobial peptide; Defensin; bBD-1; hBD-1; mBD-1; Bovine 1. IntroductionDefensins are a group of disulfide-linked cationicantimicrobial peptides that function in vertebrateinnate immunity. Mammalian defensins have beenclassified into three types which differ from eachother primarily in the spacingand connectivity ofthesix cysteine residues: a-defensins (1$ 6, 2$ 4,3 $ 5), b-defensins (l$ 5, 2 $ 4, 3 $ 6), and theprimate u-defensin (circular molecule). Thus far, no