Model Synthetic Channel Assemblies

模拟合成通道组件

• 批准号: 8268419
• 负责人: John M Tomich
• 金额: $ 29.89万
• 依托单位: KANSAS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8268419
• 关键词: Acids; Amino Acids; Anions; Area; Binding; Bio-Base; Biological; Cations; Cells; Characteristics; Charge; Chemicals; Computer Simulation; Cysteine; Cystic Fibrosis; Diffusion; Dipeptides; Disease; Electrolytes; Electrophysiology (science); Electrostatics; Environment; Epithelial; Generations; Glycine Receptors; Goals; Half-Life; Hydrogen Bonding; Ion Channel; Ion Transport; Ions; Laboratories; Lead; Length; Life; Liquid substance; Membrane; Methods; Modeling; Modification; Monitor; Monovalent Cations; Morbidity - disease rate; Movement; Outcome; Parents; Peptide Synthesis; Peptides; Pharmaceutical Preparations; Positioning Attribute; Property; Proteins; Regulation; Relative (related person); Replacement Therapy; Series; Solubility; Solutions; Source; Spinal Cord; Structure; Study models; Technology; Therapeutic; Threonine; Tight Junctions; Water; Work; alanylproline; apical membrane; aqueous; basolateral membrane; crosslink; design; extracellular; flexibility; interfacial; loss of function; monolayer; monomer; mortality; protein aminoacid sequence; public health relevance; response; simulation; solute; structural biology; synthetic peptide

DESCRIPTION (provided by applicant): The goal of this project is to design, develop and implement the use of ion-selective, synthetic channel-forming peptides. A primary application for such technology will be the treatment of loss-of-function ion channel diseases such as cystic fibrosis. Epithelial monolayer's act as barriers to the movement of small solute molecules, including both inorganic ions and drugs, between body compartments. Ions cross epithelial apical and basolateral membranes via combination of tightly regulated ion-specific transporters and channels; limited diffusion across tight junctions can occur. Loss-of-function of any channel leads to electrolyte and fluid imbalances that result in morbidity and mortality. For many years, this laboratory has been developing synthetic peptides that form pores with varying degrees of anion conduction and selectivity. These synthetic peptide sequences are distantly related to the pore-forming transmembrane segment (M2) of the spinal cord glycine receptor (GlyR) a1-subunit. We hypothesized that the ideal channel-forming sequence should:1) have high aqueous solubility as a monomer; 2)have no detectable antigenicity;3) bind to and then partition rapidly into biological membranes at low solution concentrations; 4) undergo supramolecular assembly in the membrane to form pores with high ion throughput; and 5) show physiologically relevant anion selectivity. All of these properties have been achieved with the exception of the final goal, anion selectivity. We are now exploring distinct approaches to raise the permselectivity for Cl- (PCl) relative to either Na+ or K+. Cells treated with our de novopores tolerate them well with the net anion flux controlled by the natural regulation of counter-ion transport. In the Aims we propose to modulate pore-exposed and peptide-peptide interfacial residues that dictate the pore environment, channel geometry, and channel size to generate a series of pores that define a range of perm selectivity's for Cl- relative to monovalentcations, with retention of high anion permeation rates. Specific amino acid replacements will be introduced to modulate pore lining residues with regard to hydrogen bonding capabilities or electrostatic properties. Other replacements will alterpore length and rigidity. The effects of these modifications will be monitored by a combination of electrophysiological and structural (CD & NMR) studies in conjunction with computer modeling. PUBLIC HEALTH RELEVANCE: The bio-based peptide materials described in this proposal are derived from the same biological source and undergo self assemble in both membranes and living cells to form channel pores that display unique biological properties. Producing new peptides with high anion selectivity would have translational promise in the area of channel- replacement therapy for channelopathies such as cystic fibrosis.

描述（由申请人提供）：该项目的目的是设计，开发和实施离子选择性，合成通道形成的肽的使用。这种技术的主要应用是治疗功能丧失的离子通道疾病，例如囊性纤维化。上皮单层是人体隔室之间小型溶质分子（包括无机离子和药物）运动的障碍。离子通过严格调节的离子特异性转运蛋白和通道的组合交叉上皮顶和基底外侧膜；可能会发生有限的扩散在紧密连接处。任何通道的功能丧失会导致电解质和流体失衡，从而导致发病率和死亡率。多年来，该实验室一直在开发合成肽，该肽形成不同程度的阴离子传导和选择性的毛孔。这些合成肽序列与脊髓甘氨酸受体（Glyr）A1-subunit的孔形成跨膜段（M2）遥远有关。我们假设理想的通道形成序列应：1）具有高水溶性为单体； 2）没有可检测到的抗原性； 3）在低溶液浓度下迅速与生物膜结合并迅速分配； 4）在膜上进行超分子组件，形成具有高离子吞吐量的孔； 5）表现出与生理相关的阴离子选择性。除最终目标（阴离子选择性）外，所有这些属性都已实现。我们现在正在探索不同的方法，以提高相对于Na+或K+的Cl-（PCL）的倍数。用我们的DE Novopores处理的细胞可以通过反离子运输的自然调节控制的净阴离子通量良好。在目的中，我们建议调节孔隙暴露和肽肽界面残基，这些残基决定孔环境，通道的几何形状和通道大小，以生成一系列孔，这些孔定义了相对于单人价的一系列pers选择性，并保留了高阴离子渗透率。将引入特定的氨基酸替代品，以调节有关氢键能力或静电性能的孔洞残基。其他替换将改变螺距的长度和刚性。这些修饰的效果将通过电生理和结构（CD＆NMR）研究结合计算机建模的结合来监测。 公共卫生相关性：该提案中描述的基于生物的肽材料是从相同的生物来源得出的，并在膜和活细胞中都经历了自我组装，以形成显示独特的生物学特性的通道孔。产生具有高阴离子选择性的新肽在通道替代疗法领域的通道疗法（例如囊性纤维化）的转化有望。