Protein crystallization and development of the apparatus

蛋白质结晶及装置的研制

基本信息

批准号：
07044198
负责人：
AIBARA Shigeo
金额：
$ 5.06万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044198/
关键词：
Lysozyme Protein crystal growth Vapor difusion method X-ray crystallography Molecular packing Water structure Microgravity Space shuttle 結晶成長結晶化容器

项目摘要

Crystallization experiement of hen egg-white lysozyme was conducted by using the space shuttle under the microgravity environment in space. The crystallization apparatuses were used according to the principle of the vapor diffusion method.In the crystallization conditions for growing monoclinic crystals, 2 morphologically different kinds of crystals were obtained. Furthermore, orthorhombic crystal appeared under the same crystallization conditions. On the other hand, crystals which seemed to be the orthorhombic crystal were also grown under the crystallization conditions for growing tetragonal crystals in addition to the tetragonal crystal. Of the two different shapes of monoclinic crystals, one is a rectangular form and the other is an extremely thin plate-like form. They are easily distinguished from each other by their appearances. In the space experiments, there was a strong likelihood of the latter crystals appearing. Since the molecular packing in the crystal of these two monocli … More nic lysozymes, however, revealed to be the same arrangement from the results of X-ray crystallographic analysis, the difference in the morphology between the space- and ground-grown crystals is considered to be derived from difference in the growth rate of the crystal plane. Regarding orthorhombic crystals, in contrast, the molecular packing of the space-grown crystals were quite different from that of the high temperature forms which are transformed under the temperature conditions higher than 30ﾟC from the ground-grown tetragonal or monoclinic crystals. It has been reported that the orthorhombic crystals possessing the same molecular arrangement appearred, but the resolution of the crystals is limited to 6* and no more report has been published thereafter. Next, the space-grown tetragonal crystals had the same molecular packing in the crystals as well as the same morphology as the ground-grown crystals.As the results, it turned out that crystals of the different space group happened to appear even under the same crystallization conditions in a microgravity environment in space. After X-ray crystallographic analyzes of six crystals from the three different space groups (monoclinic, orthorhombic and tetragonal forms of the space- and earth-grown crystals), their molecular structures were compared. Significant differences among the obtained molecular structures were not found between the space- and ground-grown crystals although they had some relatively fractuated regions in the molecule. Regarding the water structure bound to the protein, three highly ordered water molecules were commonly conserved in the hinge region of lysozyme. These facts suggest that the protein structure itself was not influenced by the microgravity but that the interaction of the protein molecules in the nucleation process was significantly affected. In space, it is assumed that the surface characteristics of the protein molecule e.g.the distributions of the change and the hydrophobic region on the surface of the protein molecule control the intermolecular interactions in the formation of crystal neuclei. Less

利用航天飞机在太空微重力环境下进行鸡蛋清溶菌酶的结晶实验，所用的结晶装置是根据蒸汽扩散法的原理，在生长单斜晶体的结晶条件下，采用了两种形态不同的结晶条件。另外，在相同的结晶条件下，得到了斜方晶系的晶体。除了四方晶体之外，还在生长四方晶体的结晶条件下生长了晶体。在两种不同形状的单斜晶体中，一种是矩形形状，另一种是极薄板状形状，它们很容易区分。然而，在太空实验中，由于这两种单斜溶菌酶的晶体中的分子堆积显示出相同的排列，因此很有可能出现晶体。从X射线晶体学分析的结果来看，空间生长晶体和地面生长晶体之间的形态差异被认为是源于晶面生长速率的差异，相反，是由于分子堆积。太空生长的晶体与地面生长的四方或单斜晶体在高于 30°C 的温度条件下转变的高温形式有很大不同。具有相同分子排列的斜方晶体出现了，但晶体的分辨率仅限于6*，此后没有发表更多的报道。接下来，太空生长的四方晶体在晶体中具有相同的分子堆积以及相同的结构。结果表明，在太空微重力环境下，经过X射线晶体学嵌套后，即使在相同的结晶条件下，也会出现不同空间群的晶体。来自三个不同空间群（太空和地球生长的晶体的单斜晶系、斜方晶系和四方晶系）的六种晶体，比较了它们的分子结构，在太空和地面生长的分子结构之间没有发现显着差异。尽管它们在分子中具有一些相对断裂的区域，但关于与蛋白质结合的水结构，溶菌酶的铰链区域通常保守三个高度有序的水分子，这些事实表明蛋白质结构本身。不受微重力的影响，但蛋白质分子在成核过程中的相互作用受到显着影响，假设蛋白质分子的表面特征，例如表面上的变化和疏水区域的分布。蛋白质分子控制晶核形成过程中的分子间相互作用。