Japan Aerospace Exploration Agency Protein Crystal Growth (JAXA PCG) - 01.14.15

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
The High Quality Protein Crystal Growth Experiment (JAXA PCG) aims at the growth of crystals of biological macromolecules by the counter-diffusion technique. The main scientific objective of the JAXA PCG experiment is to make high quality protein crystals under microgravity environment.
Science Results for Everyone
Protein crystallization experiments have been performed in space for more than 20 years. In this experiment, more than 300 protein samples are launched and high quality crystals successfully grown from about 80 percent of them.  It is expected that a protein depletion zone and an impurity depletion zone are formed around a crystal during protein crystal growth if the process is not disturbed by gravity, thus giving better quality crystals.  A new technique to estimate growth rate and impurity proves that, in microgravity, protein depletion and impurity depletion zones appear. Detailed analysis of high quality protein crystal structures is useful in designing new pharmaceuticals and catalysts for a wide range of industries.

The following content was provided by Shigeki Kamigaichi, and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Japan Aerospace and Exploration Agency (JAXA).
Experiment Details


Principal Investigator(s)

  • Kazunori Ohta, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan

  • Co-Investigator(s)/Collaborator(s)
  • Mitsugu Yamada, Japan Aerospace Exploration Agency, Ibaraki, Japan

  • Developer(s)
    Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan

    Sponsoring Space Agency
    Japan Aerospace Exploration Agency (JAXA)

    Sponsoring Organization
    Information Pending

    Research Benefits
    Information Pending

    ISS Expedition Duration
    March 2009 - Ongoing

    Expeditions Assigned

    Previous ISS Missions
    The precursor to JAXA PCG, JAXA GCF was completed in Russian Service Module from 2003 to 2008.

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    Experiment Description

    Research Overview

    • Under microgravity conditions, convection and sedimentation are suppressed. Therefore, diffusion areas are maintained, the density around the crystals decreases, the crystals grow slowly, the capture of impurities and microcrystal decreases, and a crystal will grow well.

    • High quality protein crsystals are obtained.

    • Using high quality crystals obtained in the space experiment, detailed information on crystal structures for designing new drugs for diseases and catalysts for ecological application are obtained.

    JAXA has developed a new technique that estimates the driving force ratio of crystals grown on the ground and in space, and the capture ratio of impurities through the diffusion/capture coefficient of protein. This technique proved that under microgravity conditions with high viscosity and slow diffusion, a protein depletion zone and impurity depletion zone appears. Using this technique researchers try to get high quality protein crystals.  The goal is to contribute to yielding results which meet the social requirements.

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    Space Applications
    The growth of protein crystals on board ISS shows the benefits of utilizing the ISS as a platform for microgravity science and research.

    Earth Applications
    This experiment contributes to society by space-grown protein crystals being used to help create new drugs for diseases, as well as the development of new catalysts for use in the industrial and energy sectors.

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    Operational Requirements
    Module within 24 hrs. The PCRF controls the temperature at 20oC. After the experiment is done, the crew removes the PCG Canisters from the PCRF cell tray, and packs Canisters for return and retrieval from Soyuz within 12 hours after landing.

    Operational Protocols
    Loading of the protein samples into the crystallization cells is done in Japan or Russia (Moscow). Installation of crystallization cells into the Crystallization Cannister at the Baikonur launch site is done, and launched on Soyuz/Progress. After docking to ISS, the crew transfers the canisters to Kibo. The crew installs canisters into the cell tray of the Protein Crystallization Research Facility (PCRF), and starts and runs the experiment for 42 to 120 days at 20°C. Crystal Growth starts automatically from the ground, no crew interaction is required. At the completion of the experiment, the crew removes canisters from the PCRF cell tray and packs the canisters for return and retrieval on Soyuz. The 3D structure of the protein crystals grown in space are analyzed at a synchrotron facility on the ground.ground.

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    Results/More Information

    Protein crystallization experiment in space environment has been performed for more than 20 years. JAXA has conducted protein crystallization experiment in ISS since 2003. In this experiment, totally over 300 protein samples were launched by Russian space transportation system and JAXA developed the technology to obtain the high quality crystals in space. JAXA also established user-friendly support service system for users to apply to the space experiment easily.About 80% proteins were crystallized in past JAXA PCG mission. This ratio is almost equal to the past protein crystallization experiment of JAXA.The excellent diffraction data to be able to analyze the protein structure newly was obtained for three kinds of proteins. Now detaled structure analysis of those proteins are conducted. The space-grown crystals will be applied structural biology and pharmaceutical activity.

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    Results Publications

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    Ground Based Results Publications

      Timofeev V, Smirnova E, Chupova L, Esipov R, Kuranova IP.  X-ray study of the conformational changes in the molecule of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis during the catalyzed reaction. Acta Crystallographica Section D: Biological Crystallography. 2012 11/09/2012; 68(12): 1660-1670. DOI: 10.1107/S0907444912040206.

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    ISS Patents

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    Related Publications

      Tanaka H, Sasaki S, Takahashi S, Inaka K, Wada Y, Yamada M, Ohta K, Miyoshi H, Kobayashi T, Kamigaichi S.  Numerical model of protein crystal growth in a diffusive field such as the microgravity environment. Journal of Synchrotron Radiation. 2013 October 1; 20(6). DOI: 10.1107/S0909049513022784.

      Takahashi S, Ohta K, Furubayashi N, Yan B, Koga M, Wada Y, Yamada M, Inaka K, Tanaka H, Miyoshi H, Kobayashi T, Kamigaichi S.  JAXA Protein Crystallization in Space: Ongoing Improvements for Growing High-quality Crystals. Journal of Synchrotron Radiation. 2013 November; 20(6): 968-973. DOI: 10.1107/S0909049513021596.

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    Related Websites
    High Quality Protein Crystallization Research (HQPC)

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    image Protein Crystallization Research Facility. Image courtesy of JAXA.
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    image High Quality Protein Crystal Growth Experiment Canister. Image courtesy of JAXA.
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    image NASA Image: ISS022E057676 - View of Japan Aerospace Exploration Agency (JAXA) Soichi Noguchi, Expedition 22 Flight Engineer (FE), during installation of Protein Crystal Growth (PCG) canister into the Protein Crystallization Research Facility (PCRF).
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    image NASA Image: ISS028E049720 -
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