The yeast cell wall maintains integrity and regulates environmental interactions through the Cell Wall Integrity (CWI) pathway. Three members of the Wsc-family of proteins (Wsc1p, Wsc2p, and Wsc3p) act as transmembrane sensors, with serine/threonine-rich motifs in their cytoplasmic tails serving as phosphorylation targets. Some research groups suggest these motifs may be act as potential antifungal targets. Gold nanoparticles (AuNPs) are promising antimicrobial agents due to their biocompatibility and low resistance development. Functionalizing AuNPs with peptides may enhance their antifungal effect. This research introduces sodium dodecyl sulphate (SDS) as a cell wall disruptor to enhance AuNPs uptake. Peptide-based AuNPs were PEG-conjugated and characterized via Zetasizer (for hydrodynamic diameter determination) and UV-Vis absorbance at 600 nm. The wild-type CFY-7 yeast strain was cultured, serially diluted, and plated onto YPD agar supplemented with chloramphenicol. Segmented petri dishes contained a control, 5X SDS either alone or with 10X (or 20X) peptide-PEG-AuNPs. Plates were incubated at 30°C and observed at 24 h intervals to monitor yeast growth. After 48 h incubation, complete yeast inhibition was observed, except with those spherical AuNPs conjugated with SSFSS, SSFS(pS), and (pS)SPSSN, suggesting that these peptides might alter SDS susceptibility. Additionally, YPD agar plates containing 5X SDS and AuNPs (or AuNPs-PEG) fully inhibited yeast growth. Future work includes TEM analysis of these spherical peptide-based AuNPs, as well as yeast susceptibility assays for detailed analysis. These findings contribute to the development of AuNPs-based antifungal strategies.
Research reported in this publication was supported by the National Institute Of General Medical Sciences of the National Institutes of Health under Award Number P20GM103475. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.