DEVELOPMENTAL RESEARCH OF THE MEASUREMENT OF WEAK X-RAY DIFFRACTION BY USE OF AN IMAGING PLATE AND A HIGH POWER ROTATING ANODE X-RAY GENERATOR

本研究旨在开发和测试用新区域探测器、成像板（IP，富士电影公司）对弱X射线差异的强度测量方法，在我们的超高强度X射线衍射实验室中，高功率旋转阳极X射线发生器90千瓦。DIP 100由Mac科学有限公司在沉积摄像机上安装了IP，并与一台以上的X射线发生器组合在一起，配有50 kV， 50 mA，在0.1X1毫米的精细焦点上运行。VAX工作站控制系统和处理测量的强度数据。首先，我们测试了几个蛋白质晶体。（i）四边形晶体：高达1.8 A^^的高分辨率数据可以在24小时内收集; 10，000个独立的反射可以在31个IP上收集总共30，000个强度记录，每一个IP的曝光， <I/ sigma（I）>-5个限制在1.8 A^的5个分辨率，合并R= 4%。这是一个快速的强度收集，高精度比预期的要多。（ii）蛋白质抑制剂蛋白的晶体：完整的强度数据可以在10小时内收集到2.2 A^^·分辨率可以在10小时内收集; 21个IP使用了25分钟的披露，每IP合并了8%。这种抑制剂晶体的质量并不是很好，而且数据分辨率的极限与收集在国家高能物理实验室光子工厂的国家实验室。这两套强度数据集是独立地用于蛋白质结构的精炼，两者都得到了相同的结果。（iii）α-淀粉酶：自从水晶非常小，-0.1毫米，没有高质量的数据集可能会出现。但这是很清楚的，即使是小晶体，这种强度测量系统也可以方便地用于测试晶体质量和重原子替换晶体。因此，该系统被发现对X射线蛋白晶体学非常有效。

This research is to develop and test a method of intensity measurement of weak X-ray diffractions with the new area detector, imaging plate (IP,Fuji film Co.), and the high-power rotating anode X-ray generator 90kW in our Ultra High Intensity X-ray Diffraction Laboratory. DIP100 made by Mac Science Co.Ltd which installs an IP on the oscillation camera was combined with the above mentioned X-ray generator operated with 50kV, 50 mA on a fine focus of 0.1X1 mm. A VAX work station controls the system and processes the measured intensity data.At first we have tested a few protein crystals. (i) Tetragonal lysozyme crystal : Intensity data of a high resolution up to1.8 A^^・ could be collected in 24 hours ; 10,000 independent reflections could be collected out of a total 30,000 intensity recorded on 31 IP's, with 40 min. exposure per an IP, <I/ sigma(I)> - 5 at the limit of 1.8 A^^・ resolution, and merging R=4%. Such a speedy intensity collection with high precision are much more than expected. (ii) a crystal of a protease inhibitor protein : A complete intensity data up to 2.2 A^^・ resolution could be collected within 10 hours ; 21 IP's were used with an exposure of 25 min. per IP, merging R was 8%. The quality of this inhibitor crystal was not so good, and this limit of resolution of the data is the same as that collected at the Photon Factory of the National Laboratory for High Energy Physics. These two intensity data sets were independently used for the refinement of the protein structure and both gave the same result. (iii) alpha-amylase : Since the crystals were very small, - 0.1 mm, no high quality data set could be obtained. But it was made clear that even for small crystals this intensity measurement system could conveniently be used for testing crystal quality and heavy atom replaced crystals.Thus, this system is found to be very effective for X-ray protein crystallography.