Work

Observation of ice-like water layers at an aqueous protein surface

Year: 2014

Type: article

Abstract: We study the properties of water at the surface of an antifreeze protein with femtosecond surface sum frequency generation spectroscopy. We find clear evidence for the presence of ice-like water layers at the ice-binding site of the protein in aqueous solution at temperatures above the freezing point. Decreasing the temperature to the biological working temperature of the protein (0 °C to -2 °C) increases the amount of ice-like water, while a single point mutation in the ice-binding site is observed to completely disrupt the ice-like character and to eliminate antifreeze activity. Our observations indicate that not the protein itself but ordered ice-like water layers are responsible for the recognition and binding to ice.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.1414188111