STRUCTURAL INVESTIGATION OF NOVEL MUTANT HEMOGLOBINS

本实验室已研制出一种高效的大肠杆菌表达系统。 重组新型突变型血红蛋白的生产 定点突变。该系统的一个目标是设计 突变体将允许我们指定核磁共振波谱中的共振峰 人类血红蛋白。因此我们设计并生产了表面a-His 杜松子酒突变的血红蛋白使我们能够将一些芳香族 共鸣。一些突变的血红蛋白已经显示出氧气的减少。 协作性，表明在 血红蛋白四聚体的亚基间区。这很有趣， 由于氨基酸取代是在血红蛋白的表面， 距离亚基间区域约30英里，太远了，任何人都不会怀疑 在血红蛋白四聚体的界面上有如此显著的影响。 我们想要研究单一氨基酸的替代是如何 表面扰乱了血红蛋白的内部位置。我们建议 用分子动力学来模拟结构的变化。我们计划 用随机边界分子动力学方法(SBMD)研究 仿真减少了处理时间。我们可能不得不下定决心 然而，在计算中包括整个蛋白质，因为它是 很难设计出既包括突变又包括突变的边界 表面的位置和亚基间表面的原子。

Our laboratory has developed an E. Coli expression system for production of recombinant novel mutant hemoglobins induced by site-specific mutagenesis. One objective of this system is to design mutants that will allow us to assign resonance peaks in NMR spectra of human hemoglobin. We have thus designed and produced surface a-His to Gin mutant hemoglobins that have enabled us to assign some aromatic resonances. Some mutant hemoglobins have shown decrease in oxygen cooperativity, suggesting significant structural perturbation at the intersubunit region of hemoglobin tetramer. This is interesting, since the amino acid substitution is on the surface of the hemoglobin, ~30  away from the intersubunit region, too far for anyone to suspect such prominent influence at the interface of the hemoglobin tetramer. We would like to investigate how a single amino acid substitution at the surface perturbs the interior sites of hemoglobin. We propose to use molecular dynamics to simulat e the structural changes. We plan to use the stochastic boundary molecular dynamics method(SBMD) for simulation to reduce the processing time. We may have to resolve to including the entire protein in the calculation, however, since it is difficult to design a boundary that will include both the mutation site at the surface and the atoms at the intersubunit surface.