New Technique Shocks Proteins Into Action

Dec 6, 2016

For a protein to carry out its job—whether it be replicating DNA, metabolizing fuel, transporting biomolecules, or sending cell signals—its amino acids have to move in certain ways. The patterns of these internal motions aren’t always well understood because the tools available to study them are limited.

A new technique, electric field-stimulated X-ray crystallography (EF-X), combines electric pulses with time-resolved X-ray crystallography to provide more comprehensive views of the ways proteins work. Electrical charges and dipoles are present in all proteins, and external electric fields can exert forces on them, causing atoms to move.

Hekstra, D. R., White, K. I., Socolich, M. A., Henning, R. W., Šrajer, V., and Ranganathan, R. (2016) Electric-field-stimulated protein mechanics. Nature 540, 400–405

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In EF-X, an electric field (E) applied to a PDZ domain in a protein crystal interacts with amino acids having negative (red) and positive (blue) charges. The interactions cause movements (small arrows) that correspond to conformational changes caused naturally by binding of a ligand (gold). Neutral amino acids are white.

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