STRUCTURAL INVESTIGATION OF NOVEL MUTANT HEMOGLOBINS

本实验室研制了一种E.大肠杆菌表达系统 诱导的重组新突变血红蛋白的产生 定点诱变。 该系统的一个目标是设计 突变体，这将使我们能够分配共振峰的NMR光谱， 人血红蛋白。 因此，我们设计并生产了表面a-His， 杜松子酒突变血红蛋白，使我们能够分配一些芳香族 共振 某些突变血红蛋白显示氧含量减少 协同性，这表明显着的结构扰动， 血红蛋白四聚体的亚基间区域。 这很有趣 由于氨基酸取代是在血红蛋白的表面上， 离亚基间区域太远了，任何人都不能 我怀疑这种显着的影响，在界面上的血红蛋白 四聚体 我们想研究单个氨基酸 表面的取代扰乱了血红蛋白的内部位点。 我们建议使用分子动力学来模拟结构 变化 我们计划使用随机边界分子动力学 方法（SBMD）进行仿真，以减少处理时间。 我们可能 必须解决在计算中包括整个蛋白质， 然而，由于很难设计一个边界， 表面的突变位点和 亚基间表面

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, $sim$30 $AA$ 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 simulate 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.