The crystal packing of two orthorhombic crystal forms, Ⅰ and Ⅱ,of hen egg-white lysozyme(E.．C．３．２．１．１７，HEWL）that appeared at growth temperatures under 293K and 310K, respectively, was studied. The form I　crystal, whose crystal packing was newly investigated in this paper, was crystallized not only in a microgravity environment but also on Earth.The crystal packing of the space-grown crystals at 293K　proved to be very similar to those of the corresponding earth-grown form I　crystals at 277K and 293K, but it was significantly different from that of the from Ⅱcrystal grown at 310K. These two orthorhombic crystal forms had a common repeating unit consisting of two molecules, but the molecular arrangement of this unit differed substantially between the forms. Crystal in a microgravity field seems to grow by the same mechanism as the form I crystal grown on Earth. To explain the difference seen for the form Ⅱ crystals, we propose a molecular-growth mechanism for HEWL　orthorhombic crystals on the basis of the hydrophobic interaction. Further, we hypothesize that the protein molecules are incorporated into the crystal nuclei to complete the common molecular contact, and so the growth unit is a monomer.

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The property change of the two kinds of silicon carbide ceramics (hot-pressed SiC (HP) and reaction-sintered SiC (RS)) after 315-day and 865-day space exposure was evaluated. Solar absorptance of the space-exposed specimens and reference specimen which were irradiated by atomic oxygen (AO) on the ground increased markedly compared with that of the blank (untreated) specimen. After 315-day exposure, surface roughness of both the space-exposed specimens and the AO-irradiated specimens increased compared with the blank specimen, but after 865-day exposure it decreased. A large number of tiny particles were observed at the grain boundary parts of the space-exposed RS silicon carbide ceramics. Surface of SiC particles of both the specimens after 865-day exposure looked smooth and covered with a different layer with wavy texture. The oxygen content of both space-exposed HP and RS specimens’ surface where was not covered by a fixture jig increased markedly compared with those of blank, AO-irradiated specimens and the covered part of the space-exposed specimens’ surface and increased with increase in space exposure duration. It is concluded that the surface of SiC specimens was oxidized mainly due to the AO-irradiation, but other contribution should be included.

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It is said that the microgravity environment has a positive effect on protein crystallization because concentration depletion zones (CDZ) are positively formed due to minimized convection fluid motion and sedimentation. However, the microgravity experiment was thought to have a limited contribution to structural biology. In the JAXA's protein crystallization project since 2002, high viscosity of the precipitant solution had positive effects on the quality of the protein crystal grown in microgravity. Thus, we developed the method for estimating ‘D/β’ for the evaluation of CDZ formation using values of the diffusion coefficient (D) and kinetic coefficient (β) by a simple experiment. The D/β indicates that CDZ is formed around the crystal in microgravity if it is low enough. Since we can predict the effects of microgravity on the protein crystal growth before performing space experiment, it is possible to select samples and crystallization conditions which have high possibility to improve the crystal quality. Moreover, if we could modify the crystallization condition to lower D/β, the improvement of the crystal quality will be expected.

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As a testbed for space environment utilization in real earnest, Japanese Experiment Module “Kibo” will be soon assembled to International Space Station (ISS) and utilized at last. It is expected that innovative technologies are brought by the “Kibo” utilization in the various field such as material, combustion, chemical, life-science, medicines, manufacturing technology and so on. JAXA set up the some frame from 1998 to get the excellent results for industrial applications using ISS. In this paper we explain the structure, result and prospect on promotion structure for private sectors users. Keyword(s)

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We are developing technology to make three-dimensional photonic crystals (3DPC) by self-organization of charged colloidal particles under microgravity condition in the International Space Station (ISS). The photonic crystals will be widely used for optical devices such as optical spectral analyzers or pulse compression/extension devices. To contribute to the industry, we put prime importance on collaboration among Industry-Academia-Government, which is the key of this space experiment project. Colloidal crystals formed by charged colloidal particles have very fragile structures. To retrieve them from the ISS, we plan to fix them by gel. As fixed with elastic gel, these soft crystals can change their grid intervals by controlled compression. In other words, one device can respond to various wavelengths of light

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Protein crystallization experiment in space has been performed for more than 20 years. Although microgravity was expected to affect crystallization process to from crystals of better quality, it could not meet the expectation of the contribution to structural biology. JAXA has started ‘JAXA-GCF project’ for protein crystallization experiment in space since 2002. In the project, we performed crystallization experiments of Alpha-Amylase, Lysozyme and other important proteins in space and obtained crystals of very high quality. We introduce this unique project, our recent result, and future aspects.

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Recent progress in protein x-ray crystallography has revealed many numbers of complex biological macromolecules. Structural biologists usually discuss the function of the molecules based on their atomic structures. However, most of these discussions are based on their structures without hydrogen, since atomic scattering factor (interaction with x-ray with atom) is proportional to the number of electrons and it is quite difficult to observe hydrogen by x-ray diffraction. Biological activities, or living process, is mostly based on chemical reaction of biological molecules. Not only biological macromolecules, but also water molecules and/or ions often play key roles in this process. Electron structure is also one of the most important information in chemical reaction. Atomic resolution (~ 1.2 Å) data are required to observe hydrogen and much higher data are required to observe electrons. Also, higher-resolution data reveals more solvent structures and more disordered structures. We are working on the development of subangstrom structural biology as a collaborative program, and crystallization under microgravity is a key tool for the project.

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Construction of large and highly oriented structure by means of self-organization of macromolecules have much attention to develop novel materials. Convection-, buoyancy- and sedimentation-free environment under microgravity contributes to give highly uniform and oriented self-organized structure. In this project, two themes based on self-organization of macromolecules are progressing. The ˆrst theme is ``Creation of well-ordered periodic crystal by block copolymer''. We are aiming to obtain highly well-ordered three-dimensional structure with sub-micron scale to produce environmental sensors, photonic sheet, and so on. The second theme is ``Creation of two dimensional nano-patterns by peptides''. In this theme, large and highly oriented two-dimensional ordered arrays would be constructed by self-assembly of designed peptides with nanometer size. The obtained structure would be applied as a template of super water repellent glass, electronic device, and so on.

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“Nanoskeleton”, which is defined as functional nanoframeworks, is expected to be high-functional materials because of the high surface area due to the pore structure and the functionality of framework itself. Our main aim is to develop Titania (TiO2) Nanoskeleton composed of pores with the diameter of 7-15 nm and crystallized frameworks. Titania Nanoskeleton has potentials as high-performance photocatalysts and high-efficient dye-sensitaized solar cell. Recently, we were successful to synthesize a hexagonal-structured crystalline (anatase) Titania Nanoskeleton with pore diameter of ~7 nm using swollen surfactant micelles (oil-solubilized micelles) and/or oil-in-water nanoemulsions as templates. In addition, multi-scale computational chemistry approachs were employed to evaluate the formation mechanism of Titania Nanoskeleton and the effect of microgravity on the Titania Nanoskeleton synthesis and their performance.

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Most of the protein crystallographers are making big efforts to improve the resolution of a crystal to resolve the protein structure as precise as possible. One of the bottle-neck of the three-dimensional structure determination is to grow high-quality crystal. In JAXA-GCF and JAXA-NewGCF crystallization experiments, we established a technique of obtaining crystals of high-quality in microgravity and grew several high-quality crystals of important proteins. Here, we describe some successful results of obtaining high-quality protein crystals in microgravity and introduce effective way of using the microgravity environment for growing high-quality protein crystals to contribute to the new drug design.

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This paper describes methodology for growing charged colloidal crystals that had been adopted in the three-dimensional photonic crystal (3DPC) space-experiments. The crystallization of charged colloids is driven by electrostatic interaction between the particles, whose magnitude is governed by experimental parameters such as the particle charge number Z, and ion concentration C. The interaction is stronger at larger Z, while it is reduced with increasing C due to the electrostatic screening effect by the ions. Z value of silica particle increases with pH. Thus, under appropriate conditions, silica colloids exhibit charge-induced crystallization by changing pH. The crystallization method used in the 3DPC space-experiments is based on the unidirectional crystal growth under gradients of Z or C. The former is enabled by diffusion of base for silica colloids. The resulting crystals consist of columnar- or cubic- crystal grains with a maximum height of a few centimeters and a maximum width of one centimeter.

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Characterization methods for colloidal photonic crystals based on light diffraction phenomena are described. Kossel diffraction and imaging spectroscopy are extensively illustrated as simple and effective methods for characterizing large colloidal crystal samples. These methods can be applied to 3-dimentional photonic crystals with colloidal particles grown in space especially for the purpose of evaluating the crystallographic homogeneity.

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JAXA, Japan Aerospace Exploration Agency, has been conducting the High-quality Protein Crystallization Project using International Space Station; ISS. JAXA has developed total technologies for obtaining high-quality protein crystals in space.The success rate of crystallization has been significantly increased to about 80% through the project. The most remarkable point was that maximum resolution was still improved by space experiment even if the ground-crystal showed excellent resolution. For Successful space experiment, total technical improvement is crusial. Especially, it is important to choose the sample which can enhance the effect of microgravity.

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Crystallization is one of the rate-limiting steps in determining a protein structure by X-ray diffraction. The counter diffusion method may be the best experimental techniques for self-exploring a wide range of crystallization conditions and optimizing the condition simultaneously by a single experiment. Microfluidic technologies have been used for development of devices based on the method for high throughput protein crystallization. Although screening of protein crystallization by the nano-liter volume counter diffusion is more useful than conventional screening, crystals grown from nano-liter volume are generally insufficient in size for diffraction studies.We developed a new protein crystallization device called “MicroChip

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Experimental apparatus for the growth and fixation of colloidal crystal under microgravity environment has been developed. This paper describes the design and fabirication of a container (cell) in which the colloidal crystal grows and the method to immobilize the grown colloidal crystal by phtogelation using LEDs. The cell has 10mmx10mm square cross section and is made of (pure) acrylyc resin which is transparent to near ultraviolet light. The grown colloidal crystal was fixed by photogelation using purple LEDs as the light source to activate photoinitiator. Gel forming reagents including the photoinitiator were added into colloidal dispersion prior to fill into the cell. the colloidal crystal is expected to use as a three- dimensional photonic crystals (3DPC) .

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