CYCLIC PEPTIDES, STRUCTURE, AND FUNCTION

董事会和长期目标是研究结构和 结晶态环肽的构象细节 使用X射线晶体学技术。 许多生物活性 自然产生的物质如激素毒素抗生素 和离子转运调节剂是或含有环肽 部分。 天然存在的肽的合成类似物可以是 它们的结构和生物活性 研究了 分子的构象与 其生物活性。 环状结构的构象研究 在不同条件下结晶的肽和比较 从其他方法获得的细节可能非常 在确定生物活性构象方面有价值。 过程 环化减少了可能的构象的数量 可用于线性对应物。 构象 环化对肽几何形状的限制使得 环肽是更好地理解 调节肽构象的基本原理， 蛋白质的基本构象特性。 许多 环状分子也与生物学上重要的金属相互作用 离子。 这些都是很好的模型，可以更好地理解 离子穿过生物膜的转移机制， 了解这些离子与肽的相互作用， proteins. 在这个项目中，结构和 一些合成的环肽的构象，其可用作 使用X射线的生物活性分子的类似物 晶体学技术被计划。 构象 这些研究获得的细节与那些 从光谱学方法中获得的信息 关于肽键的内部移动性。 构象 这些信息可用于设计环肽， 特定的生物功能，如离子载体，抗生素， 或其他有用的药物。

The board and long term objective is to study the structure and conformation details of cyclic peptides in the crystalline state using x-ray crystallographic techniques. Many biologically active naturally occuring substances like hormones, toxins, antibiotics and ion transport regulators are or contain cyclic peptide moieties. Synthetic analogs of naturally occuring peptides can be easily synthesized and their conformation and biological activity studied. The conformation of a molecule is intimately related to its biological activity. The study of the conformation of cyclic peptides crystallized under different conditions and comparison of the details with those obtained from other methods could be very valuable in determining the bioactive conformation. The process of cyclization reduces the number of possible conformations available for the linear counterpart. The conformational restrictions imposed by cyclization on the peptide geometry make cyclic peptides excellent models for better understanding the basic principles that regulate peptide conformation and the fundamental conformational properties of proteins. Many of the cyclic molecules also interact with biologically important metal ions. These sever as good models for better understanding the mechanism of ion transfer across the biological membranes and understanding the interaction of these ions with peptides and proteins. In this project, the examination of the structure and conformation of a few synthetic cyclic peptides that are useful as analogs for biologically active molecules using x-ray crystallographic techniques is planned. The conformational details obtained by these studies when compared with those obtained from spectroscopic methods may yield information regarding internal mobility of peptide bond. The conformational information may be of use in designing cyclic peptides to carry out specific biological functions such as ions carriers, antibiotics or other useful drugs.