Automatic adjusting system of high-intensity focusing mirror optics using for the collection of X-ray diffraction data from protein micro crystals

为了提高入射X射线的亮度，研制了一种计算机控制的自动镜面聚焦光学系统。结合高速X射线衍射仪DIP-100(Mac Science)，对光学性能进行了评估。理论计算表明，光学X射线的亮度是石墨单色仪的4~5倍，而实际测量的亮度是石墨单色仪的8~10倍。虽然手动调整镜面光学元件的技巧高，调整两面镜片的时间长，但采用步进电机的自动调整镜片所需时间不到手动调整镜片的一半，且重复性高。相对容易获得的晶体非常小，尺寸约为0.2x0.2x0.1 mm^3。从这种尺寸的晶体中，只能用同步加速器X射线收集衍射数据，但不能足够精确地测量，以便在没有镜面光学系统的DIP-100上进行晶体分析。利用自动镜面光学系统，即使曝光时间是同步辐射X射线测量所需时间的20倍左右，也可以用旋转阳极X射线源采集DIP-100上的晶体的衍射数据。1)从0.15_x0.10_x0.08nmm^3的碱性纤维素酶晶体中获得了与同步辐射X射线源测量结果相当的衍射值，达到了3.3*分辨率；2)从模块取代的嵌合体血红蛋白晶体(0.9_x0.1 mm^3)中获得了达到2.5*分辨率的数据；，测量了高达3.5*分辨率的约31,000个反射波，并将其合并为约11,000个独立反射波，合并R因子为0.10。

In order to increase the brilliance of incident X-ray, an automatic mirror-mirror focusing optics controlled by a computer was made. The ability of the optics was estimated in the combination of high-speed X-ray diffractometer DIP-100 (Mac science) . On the theoretical calculation, the brilliance of X-ray from the optics is 4 to 5 times higher than that from graphite monochromater, but the measured brilliance was 8 to 10 times higher. Though the manual-adjusted mirror-mirror optics requires much skill and takes long time in the adjustment of two mirrors, the automatic optics using the stepping motors was needed less than half time required for the manual adjustment, and showed high reproducibility.In general, crystallization of proteins are the neck of X-ray crystal analysis. Relatively easily obtained crystals are very small and have the size of about 0.2x0.2x0.1mm^3. From the crystals of that size, diffraction data are able to be collected only using synchrotron X-ray, but cannot be measured precisely enough for crystal analysis on DIP-100 without mirror-mirror optics. With the automatic mirror-mirror optics, diffraction data can be collected from those crystals on DIP-100 using the rotating anode X-ray source, even though the exposure time is about 20times longer than that required in the measurement using synchrotron X-ray.The examples of collected data using the mirror-mirror optics are following ; 1) from a crystal of alkaline cellulase with the size of 0.15_x0.10_x0.08nmm^3, diffraction data comparable to those measured with synchrotron X-ray source were collected up to 3.3* resolution , 2) from a crystal (0.9_x0.1mm^3) of module-substituted chimera hemoglobin, data were collected up to 2.5* resolution, 3) from a crystal (0.8_x0.3mm^3) of amidase C_<wlc>, about 31,000 reflections up to 3.5* resolution were measured and were merged to about 11,000 independent reflections with merging R-factor of 0.10.