ROLE OF ORDERED HELICAL SEGMENTS IN MEMBRANE PROTEINS

描述：（申请人摘要中的逐字记录）氯化物缺陷 上皮细胞中的转运由囊性纤维化中的突变引起， 运输调节剂（CFTR）。一种潜在的治疗囊性癌的方法 纤维化（CF）将恢复氯转运到气道上皮细胞 细胞在这种追求下，一系列水溶性阴离子传导肽 能够自发插入上皮细胞膜， 合成了这个肽家族是仿照成孔M2 跨膜段的阴离子选择性通道，脑甘氨酸受体 （M2GlyR）。为了提高疏水M2 GlyR序列的水溶性， 不同数量的赖氨酸残基被添加到C-或N- 终点站这些肽能够增加短路电流和水 跨上皮细胞的运输。拟议研究的具体目标 进一步在生物药理学上表征先导化合物CK 4-M2 GlyR， 以及通过以下方式修饰的M2 GlyR序列的变体：i）添加 各种离子基团至C-或N-末端; ii）置换或重排 iii）通过使用所有D氨基酸改变手性。 所得肽将根据对生物活性必需的性质进行评价。 CF的潜在治疗剂，包括水溶性、阴离子 选择性、膜亲和性、整体增强氯离子转运的能力 细胞，半衰期长，细胞毒性低。这个项目的长期目标 项目将使用分子建模来定义 结构和功能的M2 GlyR家族的肽，并设计一个 优化的阴离子传导肽。然后将对该化合物进行评价， 对正常及慢性阻塞性肺疾病小鼠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-脂质相互作用的了解， 随着越来越多的天然肽被 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.