BAND 3 N-TERMINAL AA 10-16 AND DEOXY S POLYMERIZATION

带 3 N 端 AA 10-16 和脱氧 S 聚合

• 批准号: 3353259
• 负责人: JOHN W HARRIS
• 金额: $ 9.48万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-02-01 至 1991-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3353259
• 关键词: chemical binding; chemical structure function; conformation; gel electrophoresis; hemoglobin Ss; polymerization; protein sequence; sickle cell anemia; synthetic peptide

The polymerization and sol-gel transformation of deoxyhemoglobin S will be inhibited by an unexplored mechanism in which the close approach of hemoglobin molecules necessary to initiate and propagate polymerization is prevented and the hemoglobin is allowed to remain fully functional. Peptides of the amino acid sequence present in the N-terminal portion of Band 3 of the human erythrocyte bind reversibly to hemoglobin A at the 2,3-DPG receptor locus. Binding to the deoxy conformation is much greater than to the oxy. The peptides extend deep into the cavity between the beta chains and, depending on length, protrude for varying distances beyond the confines of the tetrad. The interactions between fragments of the N-terminal cytoplasmic portion of Band 3 and hemoglobin S are comparable with those of hemoglobin A but the effect of such peptides on the polymerization of deoxy S has not been explored. It is postulated that 1) a 15 amino acid peptide of the same sequences as in the N-terminal cytoplasmic domain of Band 3 will enter the inter-betaS chain region a distance of 18 angstrom and protrude approximately 27 angstrom outside the molecule to occupy and occlude a hemispheric volume of 27 angstrom radius around the 2,3-DPG binding site of the betaS chains and 2) the protruding portion of the peptide will, by sheer bulk or by covering up specific interacting sites, prevent the 1-5 angstrom approaches that the surface beta 6 mutant and other contact areas must make to initiate polymerization. Additional steric impedance to hemoglobin S polymer formation may arise from 1) disordering of the beta chains in the 10-12 residues f the C-termini and in the 3 N-terminal amino acids before the A helix (Changes induced in hemoglobin A by the peptide), and 3) the formation of binary complexes of deoxyhemoglobin S molecules tethered together by the peptide in beta-to-beta chain apposition. These could not properly incorporate into the polymer. The peptides will be designed, synthesized, purified, and characterized: evaluation of reactions with hemoglobin will be by Csat, time-viscosity profile, physical properties of gel, P50, competitive binding with other polyanions, change in charge and M.W. The binding, reversibility, and steric interference will be optimized by varying the molar rations of peptide to hemoglobin, peptide length, amino acid sequence, an contour. Results will provide new data on nucleation, the polymerization reaction, and the structure of polymer and gel. A new class of inhibitors will be defined that may ultimately find applicability in controlling the intracellular polymerization basic to the pathophysiology and clinical manifestations of sickle cell disorders.

脱氧血红蛋白的聚合和溶胶 - 凝胶转化 s将被未开发的机制抑制 启动和 预防传播聚合并允许血红蛋白 保持功能齐全。 氨基酸序列的肽 存在于人类3的N末端部分 红细胞在2,3-DPG受体处与血红蛋白A可逆地结合 轨迹。 与脱氧构象的结合要大得多 氧。 肽延伸到β之间的腔深处 链条，取决于长度，距离有不同的距离 超越四分之一的范围。 之间的相互作用 带3和带的N末端细胞质部分的碎片和 血红蛋白与血红蛋白A相当，但 这种肽对脱氧s聚合的影响尚未 被探索了。 假设1）15个氨基酸肽 与N末端细胞质结构域相同的序列 乐队3将进入贝塔斯间链区域的距离为18 在外面大约27埃 分子占据并阻塞半球27埃斯特罗姆的半球体积 β链链的2,3-DPG结合位点附近的半径和2） 肽的突出部分将通过纯粹的散装或 覆盖特定的相互作用站点，防止1-5埃 接近表面Beta 6突变体和其他接触区域 必须制作以启动聚合。 其他空间阻抗 血红蛋白的聚合物形成可能来自1） C-末端的10-12残基中的β链和 A螺旋前3个N末端氨基酸（诱导的变化 血红蛋白A通过肽）和3）二进制形成 脱氧血红蛋白S分子的复合物由 β-β链链的肽中的肽。 这些不能正确 掺入聚合物中。 将设计肽， 合成，纯化和表征：反应评估 与血红蛋白有关，将通过CSAT，时间粘度概况，物理 凝胶，p50的特性与其他多个聚会的竞争结合， 负责变化和M.W.结合，可逆性和空间 通过改变 肽至血红蛋白，肽长度，氨基酸序列，A 轮廓。 结果将提供有关成核的新数据 聚合反应以及聚合物和凝胶的结构。 一个 将定义新的抑制剂类 控制细胞内聚合基本化的适用性 镰状细胞的病理生理学和临床表现 疾病。