ROLE OF ORDERED HELICAL SEGMENTS IN MEMBRANE PROTEINS

描述：（逐字摘自申请人摘要）有缺陷的氯化物 上皮细胞中的转运是囊性纤维化突变的结果 运输监管机构（CFTR）。治疗囊性囊肿的潜在方法 纤维化（CF）将恢复氯离子向气道上皮的运输 细胞。在这一追求中，一系列水溶性阴离子传导肽 能够自发插入上皮细胞膜 合成的。该肽家族以成孔 M2 为模型 阴离子选择性通道的跨膜片段，脑甘氨酸受体 （M2GlyR）。为了增强疏水性 M2GlyR 序列的水溶性， 不同数量的赖氨酸残基已添加到 C- 或 N- 终点站。这些肽能够增加短路电流和水 跨上皮细胞运输。拟议研究的具体目标 将进一步从生物物理角度将先导化合物 CK4-M2GlyR 表征为 以及通过以下方式修改的 M2GlyR 序列的变体： i) 添加 C-或N-末端有各种离子基团； ii) 更换或重新安排 跨膜残基； iii) 通过使用所有 D 氨基酸来改变手性。 所得肽将根据其必需的特性进行评估 CF 的潜在治疗剂，包括水溶性、阴离子 选择性、膜亲和力、整体增强氯离子传输的能力 细胞，半衰期长，细胞毒性低。本次活动的远期目标 项目将使用分子建模来定义之间的关系 M2GlyR 肽家族的结构和功能，并设计一个 优化的阴离子传导肽。然后将评估该化合物 对小鼠正常和CF气道上皮细胞功能的影响 和人力资源。这种深入的结构-活性研究也将增加 我们对肽-脂质相互作用的总体了解，这是一个研究领域 随着更多天然存在的肽的出现，这一点变得越来越重要 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.