The antimicrobial peptide Magainin-2 interacts with BamA impairing folding of E. coli membrane proteins

ABSTRACT: In this paper we investigated the mechanism of action of Maganin-2 (Mag-2), a well-known antimicrobial peptide isolated from the African clawed frog Xenopus laevis, by functional proteomic approaches. Several proteins belonging to E. coli macromolecular membrane complexes were identified as Mag-2 putative interactors. Among these, we focused our attention on BamA a membrane protein belonging to the BAM complex responsible for the folding and insertion of nascent β‐barrel Outer Membrane Proteins (OMPs) in the outer membrane. In silico predictions by molecular modelling and in vitro fluorescence binding and Light Scattering experiments carried out using a recombinant form of BamA confirmed the formation of a stable Mag-2/BamA complex and indicated a high affinity of the peptide for BamA. The functional implications of these interactions were investigated by two alternative and complementary approaches. The number of outer membrane proteins OmpA and OmpF produced in E. coli following Mag-2 incubation was evaluated by both western blot analysis and quantitative tandem mass spectrometry in MRM scan mode. In both experiments, a gradual decrease in outer membrane protein production with time was observed because of Mag-2 treatment.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Escherichia Coli

TISSUE(S): Cell Culture

SUBMITTER: Gabriella Pinto  

LAB HEAD: Prof. Angela Amoresano

PROVIDER: PXD037418 | Pride | 2023-03-11

REPOSITORIES: Pride