Comparative analysis of thaumatin crystals grown on earth and in microgravity.

The protein thaumatin was studied as a model macromolecule for crystallization in microgravity-environment experiments conducted on two US Space Shuttle missions (USML-2 and LMS). In this investigation, we have evaluated and compared the quality of space- and earth-grown thaumatin crystals using X-ray diffraction analyses, and characterized them according to crystal size, diffraction resolution limit and mosaicity. Two different approaches for growing thaumatin crystals in the microgravity environment, dialysis and liquid-liquid diffusion, were employed as a joint experiment by our two investigative teams.

Comparative analysis of thaumatin crystals grown on earth and in microgravity.

The protein thaumatin was studied as a model macro-molecule for crystallization in microgravity-environment experiments conducted on two US Space Shuttle missions (USML-2 and LMS). In this investigation, we have evaluated and compared the quality of space- and earth-grown thaumatin crystals using X-ray diffraction analyses, and characterized them according to crystal size, diffraction resolution limit and mosaicity. Two different approaches for growing thaumatin crystals in the microgravity environment, dialysis and liquid-liquid diffusion, were employed as a joint experiment by our two investigative teams.

The crystallographic structure of the subtilisin protease from Penicillium cyclopium.

The major extracellular protease from the fungus Pencillium cyclopium was crystallized in the presence of p-phenylmethanesulfonyl fluoride (PMSF) and investigated by X-ray diffraction analysis. It was subsequently cloned and the amino acid sequence deduced from its cDNA. Although the sequence is only 49% identical to that of proteinase K of Tritirachium album, the three-dimensional structures of the two proteases are virtually identical.

Crystallization of biological macromolecules from flash frozen samples on the Russian Space Station Mir.

One hundred eighty-three flash frozen, liquid-liquid diffusion and batch method protein and virus crystallization samples were launched aboard the Space Shuttle Discovery on June 27 (STS-71) and transferred to the Russian Space Station Mir on July 1, 1995. They were returned to earth November 20, 1995 (STS-74). Subsequent examination showed that of the 19 types of proteins and viruses investigated, 17 were crystallized during the period on Mir.

Determination of local refractive index for protein and virus crystals in solution by Mach-Zehnder interferometry.

To establish the importance of, and quantitatively evaluate, the macromolecular concentration gradients in the neighborhood of growing protein, virus, and nucleic acid crystals, a convenient, accurate, and nonintrusive method has been devised. This approach should prove particularly relevant in the rigorous comparison of crystals grown in a conventional laboratory setting with those grown in a microgravity environment. The method is based on precise determination of the local refractive index using Mach-Zehnder interferometry.