Collaborative Research: Experimental and Computational Examination of Biomimetic Peptides Acting as Anti-freeze Molecules

This award from the Environmental Chemical Sciences Program in the NSF Division of Chemistry supports this collaborative project of Profs. Daniel Knopf and Robert Grubbs at Stony Brook University and Prof. Amir Haji-Akbari at Yale University to examine and generate organic molecules that can control the freezing of water. The ability to inhibit ice formation is crucial in critical technological applications such as preservation of biological materials, food processing and storage, and preventing ice growth on exposed surfaces such as those on aircraft and offshore platforms. In nature some organisms can produce so-called antifreeze proteins (AFPs) to control ice formation allowing their survival at freezing temperatures. This collaborative project aims to understand and mimic those AFPs to allow for generation of designed synthetic antifreeze molecules that can be used in various research areas and industries. This project will train three graduate and two undergraduate students and provide a course module for a summer outreach program for high school students. The team will design AFP mimetics (AFPMs) with less complex structures than natural AFPs that can lead to practical and cost-efficient ice inhibitors and anti-icing coatings. A mechanistic understanding of the antifreezing capability will be sought by translating arrangements of hydrophilic and hydrophobic amino acid side chains found in ice-binding faces of ß-helical AFPs to peptide-polymer conjugates covering various length scales from single molecules to arrays of substrate-anchored AFPMs. Ice nucleation and ice recrystallization inhibition experiments will determine the antifreezing efficacy of synthesized biomolecules. Theoretical studies using path-sampling will resolve the water-AFP mimetic interactions on length scales similar to those in the experiments. This comprehensive approach will determine the importance of the location and strength of the hydrophobic and hydrophilic groups and the flexibility of the AFPMs for antifreezing efficacy, thereby advancing the design of biomimetics that influence ice nucleation and growth. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.