The biological function of an insect antifreeze protein simulated by molecular dynamics

  1. Michael J Kuiper  Is a corresponding author
  2. Craig J Morton
  3. Sneha E Abraham
  4. Angus Gray-Weale
  1. The University of Melbourne, Australia
  2. St Vincent's Institute of Medical Research, Australia

Abstract

Antifreeze proteins (AFP) protect certain cold-adapted organisms from freezing to death by selectively adsorbing to internal ice crystals and inhibiting ice propagation. The molecular details of AFP adsorption-inhibition is uncertain but is proposed to involve the Gibbs-Thomspon effect. Here we show by using unbiased molecular dynamics simulations a protein structure-function mechanism for the spruce budworm Choristoneura fumiferana AFP, including stereo-specific binding and consequential melting and freezing inhibition. The protein binds indirectly to the prism ice face through a linear array of ordered water molecules that are structurally distinct from the ice. Mutation of the ice binding surface disrupts water-ordering and abolishes activity. The adsorption is virtually irreversible, and we confirm the ice growth inhibition is consistent with the Gibbs-Thompson law.

Article and author information

Author details

  1. Michael J Kuiper

    Victorian Life Sciences Computation Initiative, The University of Melbourne, Carlton, Australia
    For correspondence
    mkuiper@unimelb.edu.au
    Competing interests
    The authors declare that no competing interests exist.
  2. Craig J Morton

    ACRF Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Australia
    Competing interests
    The authors declare that no competing interests exist.
  3. Sneha E Abraham

    School of Chemistry, The University of Melbourne, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  4. Angus Gray-Weale

    School of Chemistry, The University of Melbourne, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Gerhard Hummer, The Max Planck Institute of Biophysics, Germany

Version history

  1. Received: October 12, 2014
  2. Accepted: May 6, 2015
  3. Accepted Manuscript published: May 7, 2015 (version 1)
  4. Version of Record published: May 26, 2015 (version 2)

Copyright

© 2015, Kuiper et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Michael J Kuiper
  2. Craig J Morton
  3. Sneha E Abraham
  4. Angus Gray-Weale
(2015)
The biological function of an insect antifreeze protein simulated by molecular dynamics
eLife 4:e05142.
https://doi.org/10.7554/eLife.05142

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https://doi.org/10.7554/eLife.05142

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