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，研制了一种由计算机控制的自动反射聚焦光学系统。在高速x射线衍射仪DIP-100 （Mac科学）的组合中估计了光学器件的能力。理论计算表明，该光学系统的x射线光亮度是石墨单色材料的4 ~ 5倍，而实测光亮度是石墨单色材料的8 ~ 10倍。手动调节双镜反射镜光学需要较高的技巧和较长的时间，而采用步进电机的自动光学系统所需的时间不到手动调节的一半，并且具有较高的再现性。一般来说，蛋白质的结晶是x射线晶体分析的关键。相对容易获得的晶体非常小，尺寸约为0.2x0.2x0.1mm^3。从这种尺寸的晶体中，只有使用同步加速器x射线才能收集衍射数据，但如果没有镜面光学系统，则无法精确测量DIP-100上的晶体分析。使用自动反光镜光学系统，可以使用旋转阳极x射线源从DIP-100上的晶体收集衍射数据，即使曝光时间比使用同步加速器x射线测量所需的时间长约20倍。下面是使用镜-镜光学系统收集数据的例子；1)碱基纤维素酶晶体（0.15_x0.10_x0.08nmm^3）的衍射数据与同步辐射x射线源测量的衍射数据可达3.3*分辨率；2)模块取代嵌合体血红蛋白晶体（0.9_x0.1mm^3）的衍射数据可达2.5*分辨率；3)氨基酶晶体（0.8_x0.3mm^3） C_<wlc>的衍射数据可达2.5*分辨率。测量了约31,000个分辨率为3.5*的反射，并合并为约11,000个独立反射，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.