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， $sim$30$aa$远离亚基间区，任何人都无法 怀疑这种对血红蛋白界面的显著影响 四聚体。我们想要研究一种单一的氨基酸如何 表面的取代会扰乱血红蛋白的内部位置。 我们建议用分子动力学来模拟结构 改变。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。我们可能会 必须解决将整个蛋白质包括在计算中， 然而，由于很难设计包括以下内容的边界 无论是表面的突变位置还是表面的原子 子单元间曲面。

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.