Growth Inhibition Mechanism of an Ice–Water Interface by a Mutant of Winter Flounder Antifreeze Protein: A Molecular Dynamics Study

Retardation of ice crystallization by short peptides

The effect of peptides on the growth of ice crystals are studied using molecular dynamics simulations. The growth of the ice crystal is simulated at a supercooling of 14 K, and the effect of a single tetrapeptide on the growth rate is calculated. For pure ice the simulated crystal grows at a rate comparable to experiment. When a peptide molecule is added near the interface, the growth rate is diminished significantly, by up to a factor of 5 for Gly-Pro-Ala-Gly and a factor of 3 for Gly-Gly-Ala-Gly. The retardation occurs via the binding of the peptide to the ice surface, suppression of ice growth near the binding site, and eventual growth of the crystal around the bound peptide. The peptide with a proline residue is more effective in retarding the crystal growth, and this can be understood from the conformation of the peptide within the frozen ice phase after overgrowth. The simulations suggest that short peptides can be effective antifreeze agents.

Mimicking biopolymers on a molecular scale: nano(bio)technology based on engineered proteins

Proteins are ubiquitous biopolymers that adopt distinct three-dimensional structures and fulfil a multitude of elementary functions in organisms. Recent systematic studies in molecular biology and biotechnology have improved the understanding of basic functional and architectural principles of proteins, making them attractive candidates as concept generators for technological development in material science, particularly in biomedicine and nano(bio)technology. This paper highlights the potential of molecular biomimetics in mimicking high-performance proteins and provides concepts for applications in four case studies, i.e. spider silk, antifreeze proteins, blue mussel adhesive proteins and viral ion channels.