JAXA High Quality Protein Crystal Growth Demonstration Experiment (JAXA PCG Demo) - 10.11.17

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Science Objectives for Everyone
Proteins are important biological molecules that can be crystallized to provide better views of their structure. Proteins crystallized in microgravity are better organized and larger than those produced on Earth, where gravity interferes with their formation. The JAXA High Quality Protein Crystal Growth Demonstration (JAXA PCG-Demo) investigation crystallizes proteins using the counter-diffusion technique and permeation method that minimizes impurities, forming high-quality crystals for use in medical studies and ecological applications.
Science Results for Everyone
Information Pending

The following content was provided by Hiroshi Miyoshi, 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

OpNom: JAXA PCG-Demo

Principal Investigator(s)
Yoshio Wada, Japan Aerospace Exploration Agency, Japan

Matsumoto Kunihiro, JAXA, Tsukuba, Japan

Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan

Sponsoring Space Agency
Japan Aerospace Exploration Agency (JAXA)

Sponsoring Organization
Japan Aerospace Exploration Agency

Research Benefits
Earth Benefits, Scientific Discovery

ISS Expedition Duration
September 2014 - March 2016; March 2016 - September 2016

Expeditions Assigned

Previous Missions
Information Pending

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Experiment Description

Research Overview

Under microgravity conditions, the processes of convection and sedimentation are inhibited. Therefore, diffusion areas are maintained, the density around the protein crystals decreases, and the crystals have a tendency to grow slower. Fewer impurities are captured in the crystals during the growth process, and there is a decrease in the formation of secondary microcrystals. As a result, high quality protein crystals are produced in microgravity conditions as opposed to protein crystals grown under gravity conditions on Earth.
Using the high quality crystals obtained from this space experiment, detailed information on crystal structures for designing new drugs for diseases, and catalysts for ecological applications, can be obtained.

JAXA has developed a new technique that estimates the driving force ratio of crystals grown on the ground, and in space, as well as the capture ratio of impurities through the diffusion/capture coefficient of proteins. 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 the research team seeks to obtain high quality protein crystals.

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Space Applications
Protein crystals provide a three-dimensional view of a protein’s structure and function. Detailed information on protein structures benefits medical research, the energy industry, and other uses. Crystals grown in microgravity are larger and purer than those grown on Earth, making the International Space Station a unique laboratory for these efforts. Data from this investigation demonstrates the effectiveness of the International Space Station (ISS) for protein crystal growth experiments.

Earth Applications
High-quality protein crystals enable better understanding of how proteins work. Proteins can be used to create new drugs to fight diseases, benefiting patients on Earth, and to develop catalysts that drive chemical reactions, benefiting the energy industry and environmental cleanup.

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Operational Requirements and Protocols

Two sets of PCG-DEMO Bags contain the protein samples that must be kept at the temperature of 4˚C.

Loading of the protein samples into the crystallization cells is done in Japan and the launch site at Kennedy Space Center (KSC). The crystallization cells are loaded into the PCG-DEMO Bags at KSC, and launched on a Space-X Dragon spacecraft to the ISS. After docking to ISS, the crew transfers the PCG-DEMO Bags to Kibo. The crew performs procedure to start the crystallization process, installs the PCG-DEMO Bags into the Stirling-Cycle Refrigerator (FROST) and starts the experiment to run for about 30 days at 4°C. At the completion of the experiment, the crew removes the PCG-DEMO Bags from the FROST, and transfer to the Space-X Dragon spacecraft for return and retrieval. The 3D structure of the protein crystals grown in space are analyzed at a synchrotron facility on the ground.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

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Related Websites

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