2018 Fiscal Year Annual Research Report
Adaptive optics approach for high-throughput, high-resolution cryo-electron microscopy of biological macromolecules and complexes
| Project/Area Number |
18H06043
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| Allocation Type | Single-year Grants |
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| Research Institution | The University of Tokyo |
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Principal Investigator |
Danev Radostin 東京大学, 大学院医学系研究科(医学部), 教授 (50415931)
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| Project Period (FY) |
2018-08-24 – 2020-03-31
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| Keywords | cryo-electron microscopy / single particle analysis / data acquisition |
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| Outline of Annual Research Achievements |
In the first year of the project we established the necessary infrastructure for performing the research. We build a GPU computing workstation for the data processing, a data storage server and set up a microscope control system that supports scripting.
We started the experimental work using test samples, such as apoferritin. Initial testing of the new adaptive optics approach revealed that it is feasible and that data acquisition throughput improvement will be possible. We gradually implemented the new experimental scheme, starting with 4-hole beam-shift acquisition and then advancing it to 9-hole beam-shift pattern. We were able to achieve a fivefold increase in data acquisition throughput and currently are collecting more than 5,000 images per day, compared to the typical 1,000 images/day before starting this research.
Following the testing of the experimental setup, we transitioned to using the new scheme in data acquisition from actual biologically relevant samples, such as GPCR membrane proteins. The initial results are very encouraging. We were able to achieve resolutions better than 3 A and even observe dynamic complex flexibility of GPCRs. This is the first such results in the world.
As soon as the setup was running smoothly, we shared the new approach with other users of the Tokyo University cryo-EM facility and already several other laboratories are benefiting from the new technique.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
We managed to achieve a fivefold increase in data acquisition speed already in the first year of the project. We hope that by the end of the project we will be able to reach a further twofold improvement for a total of tenfold gain in performance.
Furthermore, using the new approach we have already collected several datasets from important membrane proteins, such as GPCRs. The results so far are quite remarkable and are on world-top level in terms of resolution, discrimination of different conformational states and the effect of various ligands. We are working on several manuscripts describing the results.
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| Strategy for Future Research Activity |
We plan to further improve the performance of the new beam-shift data acquisition approach and hopefully reach a tenfold increase in throughput by the end of this research. We will also continue to utilize the new method for data collection of important biological samples, such as membrane proteins. Furthermore, we plan to promote and share the technique with researchers who are planning to or are already utilizing cryo-EM in their studies. The results of this research will contribute to several scientific papers that we plan to publish this year.
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