Ng J D, Lorber B, Giege R, Koszelak S, Day J, Greenwood A, McPherson A
Structure des Macromolecules Biologiques et Mecanismes de Reconnaissance, Institut de Biologie Moleculaire et Cellulaire du CNRS, Strasbourg, France.
Acta Crystallogr D Biol Crystallogr. 1997 Nov 1;53(Pt 6):724-33.
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. Thaumatin crystals grown in a microgravity environment were generally larger in volume and the total number of crystals was less, relative to crystals grown on earth. They diffracted to significantly higher resolution and with improved diffraction properties, as judged by relative plots of I/sigma versus resolution. The mosaicity of space-grown crystals was significantly less than that of crystals grown on earth. Increased concentrations of protein in the crystallization chambers in microgravity led to larger crystals. The data presented here lend further support to the idea that protein crystals of improved quality can be obtained in a microgravity environment.
在两项美国航天飞机任务（USML - 2和LMS）中进行的微重力环境实验里，奇异果甜蛋白被作为结晶的模型大分子进行研究。在这项研究中，我们使用X射线衍射分析评估并比较了在太空和地球上生长的奇异果甜蛋白晶体的质量，并根据晶体大小、衍射分辨率极限和镶嵌性对它们进行了表征。我们的两个研究团队联合开展了一项实验，采用了两种在微重力环境中生长奇异果甜蛋白晶体的不同方法，即透析法和液 - 液扩散法。与在地球上生长的晶体相比，在微重力环境中生长的奇异果甜蛋白晶体通常体积更大，晶体总数更少。根据I/σ与分辨率的相对图判断，它们的衍射分辨率显著更高，衍射特性也有所改善。在太空中生长的晶体的镶嵌性明显小于在地球上生长的晶体。微重力环境下结晶室中蛋白质浓度的增加导致了更大的晶体。此处呈现的数据进一步支持了这样一种观点，即在微重力环境中可以获得质量更高的蛋白质晶体。
