Ice Growth Inhibition in Antifreeze Polypeptide Solution by Short-Time Solution Preheating

Area of Science:

• Biophysics
• Materials Science

Background:

• Antifreeze proteins (AFPs) inhibit ice crystal growth in cold-adapted organisms.
• Winter flounder AFP provides a model for synthetic ice growth inhibitors.
• Controlling ice formation is crucial in cryopreservation and food science.

Purpose of the Study:

• To enhance ice growth inhibition in polypeptide solutions.
• To investigate the effect of preheating on polypeptide activity and ice inhibition.
• To understand the mechanism behind enhanced ice growth inhibition.

Main Methods:

• Unidirectional freezing of polypeptide solutions at varying concentrations (0-2 mg/mL).
• Microscopic imaging of ice/solution interfaces and measurement of interface velocity.
• Simultaneous temperature measurement at the ice/solution interface.
• Analysis of polypeptide conformation and aggregate size using preheating treatments.

Main Results:

• Increasing polypeptide concentration decreased ice/solution interface temperature.
• Preheating polypeptide solutions (1-5 hours) further decreased interface temperature and enhanced ice growth inhibition.
• Preheating led to larger polypeptide aggregates without altering conformation.
• Larger aggregates promoted adsorption to the interface and wider regions of supercooled solution.

Conclusions:

• Preheating is an effective method to enhance the ice growth inhibitory activity of antifreeze polypeptides.
• The enhanced inhibition is attributed to the formation of larger polypeptide aggregates.
• This study provides insights into designing more effective synthetic antifreeze agents.