Crystallographic Studies on Calmodulin Complexed with Drugs or Oligopeptides.

简称：CaM =钙调蛋白（1）各种复合物的结晶：a）建立了Ca 2 +-CaM-氯丙嗪三元复合物生长的可重复条件。B）Ca^<2+>-CaM-蜂毒肽三元复合物的结晶和晶体学特征。c）Ca^<2+>-CaM-mastoparan三元复合物只得到球晶。(2)Ca^<2+>-CaM-氯丙嗪复合物X射线结构分析的尝试：a）在本项目开始时，我们预测异常长的c轴（178 A）可能是数据收集的严重障碍。实际上，实际数据收集表明，只有高达4 A分辨率的数据才可用于结构分析。另一次尝试使用同步辐射X射线源，它具有更窄的光束发散度，由于实验舱内温度上升过大而失败。正在计划使用某种二维探测器收集数据。B）在解决相问题的重原子衍生物中，K_2PtCl_4和Pb（CH_3COO）_2的衍生物被证明是很有前途的。(3)用离子交换HPLC法分离复合物：在DEAE-5 PW柱上，仅检测到Ca^（2+）-CaM-蜂毒素复合物，表明复合物与mastoparan之间不存在明显的结合力。(4)蜂毒肽的生化研究。a）蜂毒肽和mastoparan结合到CaM-Sepharose柱，后一种肽是稍弱的配体。B）在蜂毒肽中观察到的溶血活性在mastoparan中未观察到。

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.