TIME RESOLVED XRAY DIFFRACT: ULTRATHIN LANGMUIR BLODGETT & SARCOPLASMIC RETICUL

骨骼肌肌浆网Ca ~（2+）-ATP酶活性的研究 心肌是典型的能量依赖性离子转运 ATP酶 我们试图阐明 负责钙的能量依赖性转运的机制 使用时间分辨共振和非共振衍射的离子 水化条件下Ca ~（2+）-ATP酶的剖面结构研究 定向多层分离肌浆网， 洗涤剂增溶的 Ca ~（2+）-ATP酶。 早期实验使用弯曲磁铁源在 NSLS仅限于超过400毫秒的时间尺度。 在BioCAT双焦点的初始时间分辨研究 在APS/ANL的波荡器磁铁束线集中在确定 最短的时间框架，可以记录，同时仍然提供数据， 统计精度高。 在线的最小持续时间 快门是5毫秒。 充分可用的通量饱和富士 图像板在5毫秒曝光。 x射线衍射图 良好的统计质量记录从超薄 LB多层膜 强度100倍。 这些测试表明， 足够的通量记录50微秒的曝光使用完整的 可用通量 随后的研究使用了16通道的原型， 多元素探测器（MED）能够记录 16微秒持续时间与150纳秒的连续时间帧 帧之间的盲时间。 探测器的能力是 通过记录1024个连续的15 毫秒持续时间形成2-双层Cd-花生酸LB膜。 用时间分辨的X-射线衍射法测定了Ca ~（2+）-ATP酶 在150毫秒持续时间的连续时间帧中的多层。 笼状ATP的闪光光解被用来同步合奏。

The Ca2+-ATPase of the sarcoplasmic reticulum (SR) in skeletal and cardiac muscle is a prototypical energy-dependent ion transport ATPase. We are seeking to elucidate the details of the molecular mechanism responsible for the energy-dependent transport of calcium ions using time resolved resonance and non-resonance diffraction studies of the profile structure of the Ca2+-ATPase within hydrated oriented multilayers of isolated sarcoplasmic reticulum and vectorially-oriented single monolayers of the detergent-solubilized Ca2+-ATPase. Early experiments using bending magnet sources at the NSLS were limited to time scales of longer than 400 milliseconds. Initial time-resolved studies at the BioCAT doubly-focused undulator-magnet beamline at the APS/ANL focused on determining the minimum time-frame that could be recorded while still provide data of high statistical accuracy. The minimum duration of the in-line shutter was 5 milliseconds. The full available flux saturated a FUJI Image Plate in a 5 millisecond exposure. X-ray diffraction patterns of good statistical quality were recorded from ultra-thin Langmuir-Blodgett (LB) multilayers films by attenuating the beam intensity by 100-fold. These tests indicated that there was sufficient flux to record 50 microsecond exposures using the full available flux. Subsequent studies used the 16-channel prototype of the Multi-Element Detector (MED) which is capable of recording contiguous time frames of 16 microseconds duration with 150 nanosecond blind time between frames. The detectors capabilities were demonstrated by recording 1024 contiguous time-frames of 15 millisecond duration form a 2-bilayer Cd-Arachidate LB-flim. Time-resolved x-ray diffraction data were recorded from Ca2+-ATPase multilayers in contiguous time-frames of 150 millisecond duration. Flash photolysis of caged-ATP was used to synchronize the ensemble.