The century-old puzzle of the existence of a quasiliquid layer in the surface of ice was revisited using ice-surface binding type I antifreeze proteins with specific side chain C13 labeled methyl groups. Variable temperature dependent C13 spin lattice relaxation NMR experiments were carried out below 0 °C to probe the water molecular reorientations surrounding the methyl groups. The result shows that water molecular reorientations in ice surface are much more dynamic than those in bulk ice. This study demonstrates that antifreeze proteins can be used as a sensor to detect the dynamics of water in the surface of ice.
Bibliographical noteFunding Information:
This work is supported by NIH (Grant No. 1SC1 GM083826-01).