Crystallographic Studies on Calmodulin Complexed with Drugs or Oligopeptides.

缩写：CaM=钙调蛋白(1)各种络合物的结晶：a)建立了生长CaM-氯丙嗪三元络合物的可重复生长条件。B)对Ca~(2+)&lt；~(2+)-CaM-蜂毒素三元络合物进行了结晶和晶体结构表征。(2)尝试对Ca^&lt；2+&gt；-CaM-氯丙嗪配合物进行X射线结构分析：a)在本项目开始时，我们预测异常长的c轴(178A)可能是数据收集的严重障碍。实际数据收集表明，只有分辨率达到4A的数据才能用于结构分析。另一次使用同步辐射X射线源的尝试失败了，因为实验舱内的温升很大。同步辐射X射线源的光束发散要窄得多。正在计划使用某种二维探测器(S)收集数据。(3)离子交换高效液相色谱分离：在DEAE-5PW色谱柱上只检测到Ca~(2+)&lt；~(2+)-CaM-蜂毒素络合物，表明与马斯多芬的络合物不存在明显的结合力。(4)蜂毒素的生化研究。：a)Melitttin和mastoparan与CaM-Sepharose柱结合，后者的配基稍弱。B)未观察到蜂毒素的溶血活性，也未观察到马斯多兰的溶血活性。

Abbreviation : CaM = Calmodulin(1) Crystallization of various complexes : a)Reproducible conditions for growing Ca^<2+>-CaM-chlorpromazine ternary complex was established. b) Also, Ca^<2+>-CaM-melittin ternary complex was crystallized and crystallogrpahically characterized. c)For Ca^<2+>-CaM-mastoparan ternary complex, only spherulites were obtained.(2) Attempt at X-ray structure analysis of Ca^<2+>-CaM-Chlorpromazine complex : a) At the outset of this project, we predicted that the unusually long c-axis (178 A) can be a serious obstacle for data collection. The actual data collection, in fact, showed that only the data up to 4 A resolution can be usable for structure analysis. Another attempt using the synchrotoron radiation X-ray source, which has much narrower beam divergence, failed due to large temperature rise inside the experimentation hatch. Data collection using some kind of two-dimensional detector(s) are being planned. b) Regarding the heavy-atom derivatives for solving the phase problem, the K_2PtCl_4 and Pb(CH_3COO)_2 derivatives were proved to be promising.(3) Separation of the complexes through the use of ion exchange HPLC : ONLY the Ca^<2+>-CaM-melittin complex was detcted on the HPLC patterm using DEAE-5PW column, indicating that significant binding forces were not existent in the complexes with mastoparan.(4) Some biochemical studies on melitttin, mastoparan. : a) Melitttin as well as mastoparan binds to CaM-Sepharose column, the latter peptide being slightly weaker ligand. b) Hemolytic activity observed for melittin was not observed for mastoparan.