ROLE OF ORDERED HELICAL SEGMENTS IN MEMBRANE PROTEINS

描述：(逐字摘自申请人的摘要)有缺陷的氯化物 囊性纤维化中突变导致的上皮细胞转运 运输监管机构(CFTR)。一种潜在的治疗囊性疾病的方法 纤维化(CF)将恢复氯向呼吸道上皮的运输 细胞。在这一追求中，一系列水溶性阴离子传导多肽 能够自发地插入到上皮细胞膜中 合成的。这一多肽家族是以造孔剂M2为模型的 阴离子选择性通道的跨膜片段，大脑甘氨酸受体 (M2GlyR)。为了提高疏水性M2GlyR序列的水溶性能， 不同数量的赖氨酸残基被添加到C-或N- 终点站。这些多肽能够增加短路电流和水 跨上皮细胞的运输。拟议研究的具体目标 进一步从生物物理角度表征先导化合物CK4-M2GlyR AS 以及通过以下方式修改的M2GlyR序列的变体：i)添加 C-端或N-端的各种离子基团；ii)取代或重排 跨膜残基；iii)通过使用所有D氨基酸改变手性。 所产生的多肽将根据对 潜在的治疗CF的药物包括水溶性、阴离子 选择性、膜亲和力、增强氯离子整体转运的能力 细胞，半衰期长，细胞毒性低。这样做的长期目标是 项目是使用分子建模来定义 M2GlyR家族多肽的结构和功能 优化的阴离子传导肽。然后将对该化合物进行评估 丹参对小鼠正常和CF型呼吸道上皮细胞功能的影响 和人力资源。这一深入的结构-活性研究也将增加 我们对肽-脂相互作用的总体知识是一个研究领域 这一点变得越来越重要，因为更自然产生的多肽 发现具有通道形成活性。

DESCRIPTION: (Verbatim from the Applicant's Abstract) Defective chloride transport in epithelial cells results from mutations in the cystic fibrosis transport regulator (CFTR). A potential approach for treatment of cystic fibrosis (CF) would be to restore chloride transport to airway epithelial cells. In this pursuit, a series of water-soluble anion-conducting peptides capable of spontaneous insertion into epithelial cell membranes have been synthesized. This family of peptides is modeled after the pore-forming M2 transmembrane segment of a anion-selective channel, the brain glycine receptor (M2GlyR). To enhance the aqueous solubility of the hydrophobic M2GlyR sequence, various numbers of lysine residues have been added to either the C- or N- terminus. These peptides are able to increase short-circuit currents and water transport across epithelial cells. The specific aims of the proposed research are to further characterize, biophysically, the lead compound CK4-M2GlyR as well as variants of the M2GlyR sequence that are modified by: i) additions of various ionic groups to the C- or N-terminus; ii) replacement or rearrangement of transmembrane residues; iii) changing chirality by using all D amino acids. The resulting peptides will be evaluated in terms of properties essential for a potential therapeutic agent for CF including aqueous solubility, anion selectivity, membrane affinity, ability to enhance chloride transport in whole cells, long half-life and low cytotoxicity. The long-range goals of this project are to use molecular modeling to define the relationships between structure and function for the M2GlyR family of peptides and to design an optimized anion-conducting peptide. This compound will then be evaluated for its effects on the function of normal and CF airway epithelial cells from mouse and human sources. This in depth structure-activity study will also increase our knowledge about peptide-lipid interactions in general, an area of research that becomes increasingly important as more naturally occurring peptides are found to have channel-forming activity.