title: Model membrane interaction and DNA-binding of antimicrobial peptide Lasioglossin II derived from bee venom.
abstract: Lasioglossins, a new family of antimicrobial peptide, have been shown to have strong antimicrobial activity with low haemo-lytic and mast cell degranulation activity, and exhibit cytotoxic activity against various cancer cells in vitro. In order to understand the active conformation of these pentadecapeptides in membranes, we have studied the interaction of Lasioglossin II (LL-II), one of the members of Lasioglossins family with membrane mimetic micelle Dodecylphosphocholine (DPC) by fluorescence, Circular Dichroism (CD) and two dimensional (2D) (1)H NMR spectroscopy. Fluorescence experiments provide evidence of interaction of the N-terminal tryptophan residue of LL-II with the hydrophobic core of DPC micelle. CD results show an extended chain conformation of LL-II in water which is converted to a partial helical conformation in the presence of DPC micelle. Moreover we have determined the first three-dimensional NMR structure of LL-II bound to DPC micelle with rmsd of 0.36Å. The solution structure of LL-II shows hydrophobic and hydrophilic core formation in peptide pointing towards different direction in the presence of DPC. This amphipathic structure may allow this peptide to penetrate deeply into the interfacial region of negatively charged membranes and leading to local membrane destabilization. Further we have elucidated the DNA binding ability of LL-II by agarose gel retardation and fluorescence quenching experiments.
authors.affiliation: School of Applied Sciences, Republic Polytechnic, Singapore.
authors.forename: Susmita
authors.initials: S
authors.lastname: Bandyopadhyay
authors.forename: Meryl
authors.initials: M
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Sivaraman
authors.forename: Chiradip
authors.initials: C
authors.lastname: Chatterjee
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000302:isolation & purification; D001514:Bee Venoms / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification; D024202:Electrophoretic Mobility Shift Assay; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry; D008823:Micelles; D019906:Nuclear Magnetic Resonance, Biomolecular; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000737:chemistry; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D014364:Tryptophan / Q000737:chemistry
chemical_list: D023181:Antimicrobial Cationic Peptides; D001514:Bee Venoms; D004268:DNA-Binding Proteins; D008051:Lipid Bilayers; D008823:Micelles; C545066:lasioglossin II; D010767:Phosphorylcholine; C028810:dodecylphosphocholine; D014364:Tryptophan; D004247:DNA