Hyperactive Antifreeze Proteins Promote Ice Growth before Binding to It

Area of Science:

• Biophysics
• Materials Science
• Structural Biology

Background:

• Antifreeze proteins (AFPs) are crucial for organisms surviving cold environments.
• The synergistic mechanisms between AFPs and ice crystals are not fully understood.
• Interfacial water dynamics during ice inhibition by AFPs require detailed investigation.

Purpose of the Study:

• To investigate the atomic-level synergy between the insect antifreeze protein (TmAFP) and ice crystals.
• To elucidate the role of interfacial water in the ice growth inhibition process.
• To compare the cooperative effects of TmAFP, its mutant, and a nonantifreeze protein.

Main Methods:

• Atomistic simulations of TmAFP, its mutant, and a nonantifreeze protein interacting with ice.
• Analysis of interfacial water structure and dynamics.
• Investigation of protein-ice binding and ice surface morphology changes.

Main Results:

• TmAFP exhibits significant synergy with ice, promoting ice growth before adsorption.
• A unique anchored clathrate motif forms at the interface, binding TmAFP to the ice surface.
• Three distinct stages (promotion, adsorption, inhibition) characterize TmAFP's ice growth inhibition process.

Conclusions:

• The study reveals a novel synergistic mechanism between TmAFP and ice crystals.
• This synergy, involving specific interfacial water structuring, is key to effective ice inhibition.
• Findings provide insights for designing advanced bioinspired antifreeze materials and proteins.