BRYOSTATIN BINDING SITE OF PKC AND BRYOSTATIN AN

海洋天然产品Bryostatin正在进行第二阶段临床试验 英国因治疗癌症而获奖。非常低的自然丰度 这类化合物，十亿分之几到几百份 每十亿个，而一个成员的冗长合成可能会阻碍更广泛的 临床研究。 Bryostins广泛的生物学效应可追溯到与 蛋白激酶C(PKC)。PKC的规模和复杂性排除了详细的 佛波醇酯/甘油二酯结合结构域的X射线研究 结晶学或核磁共振。较小的多肽(约50个残基) 结合这个亚区可以用核磁共振进行研究。的约束性 将用[26-~3H]-Bryostatin对这些多肽进行定量 用13C，15N标记的多肽进行核磁共振定性。作为媒介 其中一种多肽的拆分结构已掌握， 其Bryostatin结合域的确切结构的测定是 一个合理的目标。一旦知道了结合部位，那么构象 可通过二维核磁共振测定该部位的Bryostatin的含量。了解这一点 配合到结合部位将能够制造简化的类似物， 合并绑定所需的功能。潜在的路径 文中还提供了有用的类比。

The marine natural product, bryostatin, is in Phase II clinical trials in Britain for the treatment of cancer. The very low natural abundance of this class of compounds, a few parts per billion to several hundred parts per billion, and a lengthy synthesis of one member may hinder wider clinical studies. Bryostatins wide variety of biological effects is traced to binding to PKC(protein kinase C). The size and complexity of PKC precludes detailed investigation of its phorbol ester/diacylglycerol binding domain by X-ray crystallography or NMR. Smaller peptides (approximately 50 residues) which incorporate this subdomain can be studied by NMR. The binding of bryostatin to these peptides will be quantified using [26-3H]-bryostatin and qualitatively by NMR using 13C, 15N labeled peptides. As a medium resolution structure of one of these peptides is in hand, the determination of the exact structure of its bryostatin binding domain is a reasonable goal. Once the binding site is known, then the conformation of bryostatin in this site can be determined by 2-D NMR. Knowledge of this fit to the binding site will enable simplified analogs to be made which incorporate the features necessary for binding. Routes to potentially useful analogs are provided.