The structure of human beta-defensin-2 shows evidence of higher order oligomerization.

摘要: Defensins are small cationic peptides that crucial components of innate immunity, serving as both antimicrobial agents and chemoattractant molecules. The specific mechanism activity involves permeabilization bacterial membranes. It has been postulated individual monomers oligomerize to form a pore through anionic membranes, although the evidence is only indirect. Here, we report two high resolution x-ray structures human β-defensin-2 (hBD2). phases were experimentally determined by multiwavelength anomalous diffraction method, utilizing novel, rapid method derivatization with halide ions. Although shape charge distribution monomer similar those other defensins, an additional α-helical region makes this protein topologically distinct from mammalian α- β-defensin reported previously. hBD2 forms dimers neutrophil peptide-3. quaternary octameric arrangement conserved in crystal forms. These provide first detailed description dimerization β-defensins, postulate mode representative β-defensins. structural electrostatic properties octamer support charge-based membrane rather than based on formation bilayer-spanning pores.