First 3D Images of a Single Protein

3-D images from a single particle (A) a series of images of an ApoA-1 protein particle, taken from different angles as indicated. A succession of four computer enhancements (projections) clarifies the signal. In the right column is the 3-D image compiled from the clarified data. B) is a close-up of the reconstructed 3-D image. C) Analysis shows how the particle structure is formed by three ApoA-1 proteins (red, green, blue noodle-like models)

At the Molecular Foundry, Berkeley Lab’s acclaimed nanotechnology research center, Ren has pushed his Zeiss Libra 120 Cryo-Tem microscope to resolutions never envisioned by its German manufacturers.

The snapshots produced some unique images of detailed individual molecules which were only "seen", till today, through proteins models using X-ray diffraction, nuclear magnetic resonance, and conventional cryo-electron microscope (cryoEM) imaging.

Today, Ren and his colleague Lei Zhang are reporting the first 3-D images of an individual protein ever obtained with enough clarity to determine its structure.

He calls his technique “individual-particle electron tomography,” or IPET. The work is described in the January 24 issue of PLoS One, the open-source scientific journal, in an article entitled “IPET and FETR: Experimental Approach for Studying Molecular Structure Dynamics by Cryo-Electron Tomography of a Single-Molecule Structure.”  more here