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

ABSTRACT: 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.

SUBMITTER: Kuiper MJ

PROVIDER: S-EPMC4442126 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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

Kuiper Michael J MJ Morton Craig J CJ Abraham Sneha E SE Gray-Weale Angus A

eLife 20150507

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 meltin ...[more]

PMID: 25951514

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