American Chemical Society
bm300366f_si_007.mpg (5.01 MB)

Local Ice Melting by an Antifreeze Protein

Download (5.01 MB)
posted on 2012-07-09, 00:00 authored by Matteo Calvaresi, Siegfried Höfinger, Francesco Zerbetto
Antifreeze proteins, AFP, impede freezing of bodily fluids and damaging of cellular tissues by low temperatures. Adsorption-inhibition mechanisms have been developed to explain their functioning. Using in silico Molecular Dynamics, we show that type I AFP can also induce melting of the local ice surface. Simulations of antifreeze-positive and antifreeze-negative mutants show a clear correlation between melting induction and antifreeze activity. The presence of local melting adds a function to type I AFPs that is unique to these proteins. It may also explain some apparently conflicting experimental results where binding to ice appears both quasipermanent and reversible.