Aims: To identify the main amino acids involved in the Flo11p-mediated adhesion of Saccharomyces cerevisiae to the polystyrene surface PolySorp.

Methods and Results: Using a combination of phage display and competitive elution revealed that 12-mer peptides of phages from competitive panning with S. cerevisiae FLO11 wild-type (TBR1) cells had a higher consensus than those from competitive panning with S. cerevisiae flo11¿ mutant (TBR5) cells, suggesting that the wild-type cells interact with the plastic surface in a stronger and more similar way than the mutant cells. Tryptophan and proline were more abundant in the peptides of phages from competitive elution with FLO11 cells than in those from competitive elution with flo11¿ cells. Furthermore, two phages with hydrophobic peptides containing 1 or 2 tryptophan, and 3 or 5 proline, residues inhibited the adhesion of FLO11 cells to PolySorp more than a phage with a hydrophobic peptide containing no tryptophan and only two proline residues.

Conclusions: Our results suggest a key role of tryptophan and proline in the hydrophobic interactions between Flo11p on the S. cerevisiae cell surface and the PolySorp surface.

Significance and Impact of the Study: Our study may contribute to the development of novel strategies to limit yeast infections in hospitals and other medical environments.