TY - JOUR TI - The biological function of an insect antifreeze protein simulated by molecular dynamics AU - Kuiper, Michael J AU - Morton, Craig J AU - Abraham, Sneha E AU - Gray-Weale, Angus A2 - Hummer, Gerhard VL - 4 PY - 2015 DA - 2015/05/07 SP - e05142 C1 - eLife 2015;4:e05142 DO - 10.7554/eLife.05142 UR - https://doi.org/10.7554/eLife.05142 AB - Antifreeze proteins (AFPs) 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–Thomson 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–Thomson law. KW - antifreeze protein KW - crystallization inhibition KW - molecular dynamics KW - ice-binding KW - thermal hysteresis JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -