Chiral Modulation of Phenol Soluble Modulin Self-Assembly

Staphylococcus aureus biofilms have been implicated in numerous nosocomial and community associated infections worldwide. The virulence of S. aureus biofilms is dependent on the secretion of short, amphipathic peptides called Phenol-soluble modulins (PSM). PSMs provide a structural scaffold for S. aureus biofilms through fibrillation into amyloid-like fibers. Besides biofilm structuring, PSMs have other biological functions including triggering an inflammatory response, lysing mammalian cells, and show antibacterial activity towards other microbes. In this work, chiral carbon nanoparticles (CNPs) are explored for their enantioselective effect on the self-assembly process of PSM peptides. We assess the physicochemical properties of PSMa1-4 after co-incubation with chiral CNPs both as individual peptides and mixed together. With this, the fibrillation kinetics of nanoparticle-treated PSMs are assessed and the secondary structure is analyzed using circular dichroism. TEM images reveal asymmetrical hierarchical self- assembly of PSMs and chiral CNPs into supramolecular structures.