Acquisition of an X-Ray Area Detector

要求为购置一台x射线区域探测器提供财政支助，该探测器将与现有的旋转阳极发生器Rigaku RU-200一起使用。图像检测技术的最新进展使面积探测器衍射仪成为收集大分子晶体x射线数据的首选仪器。事实上，这些仪器的普及是最近观察到的每年发表的蛋白质结构数量迅速增加的主要原因。在南卡罗来纳州没有x射线区域探测器。我们目前选择的探测器是Rigaku生产的R-AXIS II，由Molecular Structure Corporation销售。由此产生的设备将作为南卡罗来纳大学生物研究与技术研究所的x射线衍射实验室运行。该设备将主要用于测定生物大分子的晶体结构。直接应用包括一系列酶的研究：氯过氧化物酶/去卤酶，甲酰基四氢叶酸合成酶，转羧化酶，烯醇化酶，谷氨酰胺酶/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蛋氨酸和碲色氨酸的形式与蛋白质的生物结合。近年来，区域探测器也经常用于“小分子”晶体学。使用Mo - K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”，如与有机配体的金属团簇配合物，区域探测器，甚至与Cu K辐射，提供了重要的优势。我们希望利用面积探测器收集数据，用于在x射线束中分析单位胞尺寸大且稳定性差的金属团簇的结构。化学与生物化学系每两年开设研究生课程CHEM745“晶体学入门”。1993年春季，学校招收了10名学生。区域探测器衍射仪将用于训练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.