title: QCM-D fingerprinting of membrane-active peptides.
abstract: The increasing prevalence of antibiotic-resistant bacteria is becoming a public health crisis. Antimicrobial peptides (AMPs) are a promising solution, because bacterial resistance is less likely. Quartz crystal microbalance with dissipation monitoring (QCM-D) is a versatile and valuable technique for investigation of these peptides. This article looks at the different approaches to the interpretation of QCM-D data, showing how to extract the maximum information from the data. Five AMPs of diverse charge, length and activity are used as case studies: caerin 1.1 wild-type, two caerin 1.1 mutants (Gly15Gly19-caerin 1.1 and Ala15Ala19-caerin 1.1), aurein 1.2 and oncocin. The interaction between the AMP and a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membrane is analysed inter alia using frequency-dissipation plots (∆f-∆D plots) to ascertain the mechanism of action of the AMP. The ∆f-∆D plot can then be used to provide a fingerprint for the AMP-membrane interaction. Building up a database of these fingerprints for all known AMPs will enable the relationship between AMP structure and membrane activity to be better understood, hopefully leading to the future development of antibiotics without bacterial resistance.
authors.affiliation: School of Chemistry, Monash University, Clayton, VIC 3800, Australia.
authors.forename: George A
authors.initials: GA
authors.lastname: McCubbin
authors.forename: Slavica
authors.initials: S
authors.lastname: Praporski
authors.forename: Stefania
authors.initials: S
authors.lastname: Piantavigna
authors.forename: Daniel
authors.initials: D
authors.lastname: Knappe
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
authors.forename: John H
authors.initials: JH
authors.lastname: Bowie
authors.forename: Frances
authors.initials: F
authors.lastname: Separovic
authors.forename: Lisandra L
authors.initials: LL
authors.lastname: Martin
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D023181:Antimicrobial Cationic Peptides / Q000032:analysis* / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; C551620:oncocin; D004134:Dimyristoylphosphatidylcholine