Free energy barriers for anti-freeze protein engulfment in ice: Effects of supercooling, footprint size, and spatial separation

Hossam Farag, Baron Peters

Research output: Contribution to journalArticlepeer-review

Abstract

Anti-freeze proteins (AFPs) protect organisms at freezing conditions by attaching to the ice surface and arresting its growth. Each adsorbed AFP locally pins the ice surface, resulting in a metastable dimple for which the interfacial forces counteract the driving force for growth. As supercooling increases, these metastable dimples become deeper, until metastability is lost in an engulfment event where the ice irreversibly swallows the AFP. Engulfment resembles nucleation in some respects, and this paper develops a model for the "critical profile"and free energy barrier for the engulfment process. Specifically, we variationally optimize the ice-water interface and estimate the free energy barrier as a function of the supercooling, the AFP footprint size, and the distance to neighboring AFPs on the ice surface. Finally, we use symbolic regression to derive a simple closed-form expression for the free energy barrier as a function of two physically interpretable, dimensionless parameters.

Original languageEnglish (US)
Article number094501
JournalJournal of Chemical Physics
Volume158
Issue number9
DOIs
StatePublished - Mar 7 2023

ASJC Scopus subject areas

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Free energy barriers for anti-freeze protein engulfment in ice: Effects of supercooling, footprint size, and spatial separation'. Together they form a unique fingerprint.

Cite this