Functional Importance of Short-Range Binding and Long-Range Solvent Interactions in Helical Antifreeze Peptides

• Published in: Biophysical journal Vol. 103; no. 2; pp. L20 - L22
• Main Authors: Ebbinghaus, Simon, Meister, Konrad, Prigozhin, Maxim B., DeVries, Arthur L., Havenith, Martina, Dzubiella, Joachim, Gruebele, Martin
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 18.07.2012; Biophysical Society; The Biophysical Society
• Subjects: Absorption; Amino Acid Sequence; Animals; antifreeze proteins; Antifreeze Proteins - chemistry; Antifreeze Proteins - metabolism; Binding sites; Biophysical Letter; Buffers; Circular Dichroism; data collection; energy transfer; Flounder; Fluorescence Resonance Energy Transfer; Freezing; freezing point; hysteresis; ice; molecular dynamics; Molecular Dynamics Simulation; Molecular Sequence Data; mutants; Mutation; Mutation - genetics; Peptides; Protein Binding; Protein Structure, Secondary; Proteins; Pseudopleuronectes americanus; Simulation; Solvents; Solvents - metabolism; spectroscopy; Water - chemistry
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1016/j.bpj.2012.06.013

Short-range ice binding and long-range solvent perturbation both have been implicated in the activity of antifreeze proteins and antifreeze glycoproteins. We study these two mechanisms for activity of winter flounder antifreeze peptide. Four mutants are characterized by freezing point hysteresis (activity), circular dichroism (secondary structure), Förster resonance energy transfer (end-to-end rigidity), molecular dynamics simulation (structure), and terahertz spectroscopy (long-range solvent perturbation). Our results show that the short-range model is sufficient to explain the activity of our mutants, but the long-range model provides a necessary condition for activity: the most active peptides in our data set all have an extended dynamical hydration shell. It appears that antifreeze proteins and antifreeze glycoproteins have reached different evolutionary solutions to the antifreeze problem, utilizing either a few precisely positioned OH groups or a large quantity of OH groups for ice binding, assisted by long-range solvent perturbation.