(112b) Self-Assembly and Rearrangement of a Polyproline II Helix Peptide on Gold
AIChE Annual Meeting
2021
2021 Annual Meeting
Engineering Sciences and Fundamentals
Biomolecules at Interfaces
Monday, November 8, 2021 - 12:45pm to 1:00pm
Polyproline peptide sequences have gained popularity as anchors for peptide-based self-assembled monolayers (SAMs) due to their attractive packing properties. In this work, peptides containing the polyproline II helix (PPII) conformation were designed and assembled on gold (Au). A quartz crystal microbalance with dissipation was used to characterize SAM formation kinetics and related properties. Peptides were designed with the sequence (GPP-P-PPG)2C. It was discovered that a biexponential adsorption and rearrangement model describes the binding kinetics of the PPII-containing peptide on Au. In this model, an initial reversible binding step is followed by an irreversible rearrangement step, given by parameter kt. This study found kt to be approximately 0.00064 s-1 for the PPII-containing peptides. Similarly, we found that the adsorption of the PPII-containing peptide on Au â given by ÎGads â was thermodynamically favorable (-7.8 kcal mol-1), and comparable to other common thiol terminated SAMs on Au. Furthermore, we characterized SAM properties via QCM-D, Fourier-transform infrared (FTIR) spectroscopy and electrochemical techniques to reveal well-packed SAMs consisting of PPII helices. Last, these SAMs were found to have high antifouling properties. Overall, this study characterizes the fundamental assembly mechanisms, particularly rearrangement, of PPII-containing peptides for the first time, which will be useful when designing future peptide-based SAMs with high packing and antifouling properties.