Acquisition of an X-Ray Area Detector

申请财政支助，用于购置X射线区域探测器，与现有的旋转阳极发生器Rigaku RU-200配合使用。图像检测技术的最新进展使面探测器衍射仪成为高分子晶体X射线数据收集的首选仪器。事实上，这些仪器的激增是最近观察到的每年发表的蛋白质结构数量快速增加的主要原因。南卡罗来纳州没有X射线区域探测器。 我们目前选择的检测器是Rigaku生产的R-AXIS II，由Molecular Structure Corporation销售。由此产生的设施将作为南卡罗来纳州大学生物研究和技术研究所的X射线衍射实验室运行。该设施将主要用于生物大分子的晶体结构测定。直接应用包括一系列酶的研究：氯过氧化物酶/脱卤酶，甲酰四氢叶酸合成酶，转羧酶，烯醇酶，天冬酰胺酶/天冬酰胺酶，前列腺酸性磷酸酶和胸苷酸合成酶。我们还将研究碲以衍生氨基酸碲甲硫氨酸和碲甲硫烷的形式生物掺入蛋白质中。 最近，面积探测器也经常用于“小分子”晶体学。使用钼钾辐射，他们通常提供与传统衍射仪一样好的数据集，但时间要短得多。对于大的“小分子”，如金属簇与有机配体的配合物，面积探测器，甚至与铜K辐射，提供了重要的优势。我们希望使用面探测器来收集数据，用于分析具有大晶胞尺寸和在X射线束中稳定性差的金属团簇的结构。 化学和生物化学系每两年提供一次研究生课程CHEM 745“介绍晶体学”。 1993年春季，招收了10名学生。区域检测器衍射仪将用于培训学生掌握最先进的数据收集技术。

Financial support is requested for acquisition of an X-ray area detector to be used with an existing rotating anode generator Rigaku RU-200. Recent advances in image detection technology have made area detector diffractometers the instrument of choice for X-ray data collection for crystals of macromolecules. Indeed, the proliferation of these instruments is the major reason for the recently observed rapid increase in the number of protein structures published annually. There is no X-ray area detector in the State of South Carolina. Our present selection of the detector is R-AXIS II produced by Rigaku and marketed by the Molecular Structure Corporation. The resulting facility will be operated as X-ray Diffraction Laboratory of Institute of Biological Research and Technology at the University of South Carolina. The facility will be used primarily for the crystallographic structure determination of biological macromolecules. Immediate applications include studies of a series of enzymes: chloroperoxidase/dehalogenase, formyltetrahydrofolate synthase, transcarboxylase, enolase, glutaminase/asparaginase, prostatic acid phosphatase, and thymidylate synthase. We will also study the bioincorporation of tellurium into proteins in the form of derivatized amino acids telluromethionine and tellurotryptophane. Recently, area detectors are frequently used also in "small molecules" crystallography. With Mo K radiation, they routinely provide data sets as good as conventional diffractometers but in much shorter time. For large "small molecules" such as metal cluster complexes with organic ligands, area detectors, even with Cu K radiation, offer important advantages. We would like to use the area detector to collect data for the structure analyses of metal clusters with large unit cell dimensions and poor stability in the X-ray beam. The Department of Chemistry and Biochemistry offers graduate course CHEM745 "Introductory Crystallography" every second year. In Spring 1993 the enrollment was 10 students. The area detector diffractometer will be used to train students in state-of-the art data collection techniques.