STRUCTURAL ENERGETICS OF HEMOGLOBIN INTERMEDIATES

这项研究的目标是确定分子规则和驱动 调节蛋白质复合体生物功能的力量。人类 正在对血红蛋白(Hb)进行研究，以了解(I)中间体 亚基相互作用产生生理性的状态和途径 协作性，以及(Ii)中间体的机制是如何 受生理效应物(H，CO2，C1-)的调节。本节目 包括：(A)开发分析能量的新方法 中间体四聚体对协作性的贡献； 由此产生的特定部位的能量学与伴随的相关性 结构变化；c使用单一氨基酸修饰来探测 调节Hb能量组分的结构元素 协作性。我们早期的工作发现，Hb的结构开关 遵循特定的组合规则：用单一氨基酸进行研究 对结合中间体的修饰揭示了重要的 Hb四聚体结构能量学的对称性/不对称性 。我们计划使用设计好的重组乙肝病毒来扩展这些研究 O2中间体的改变残基位置的组合。亚单位 重组系统的相互作用将通过技术进行研究。 杂交、组装和动力学，以及直接氧气 有约束力的。结构特征将通过X射线结晶学进行分析。 HB监管系统是一个大家庭的重要原型 合作的多地点监管集会。因此，这些方法 用这个程序开发的，应该有广泛的适用性。更深 对人类Hb机制的理解也是目前感兴趣的 潜在的红细胞替代氧载体和药物的设计 传输系统。

The goal of this research is to determine molecular rules and driving forces that regulate biological functions of protein complexes. Human hemoglobin (Hb) is being studied to understand (i) the intermediate states and pathways whereby subunit interactions generate physiological cooperativity, and (ii) how mechanisms of the intermediates are modulated by physiological effectors (H+, CO 2, C 1-). This program includes: (a) development of new methods to analyze energetic contributions to cooperativity by the intermediate tetamers; (b) correlation of the resulting site-specific energetics with accompanying structure changes; c usage of single amino acid modifications to probe structural elements which mediate the energetic components of Hb cooperativity. Our earlier work found that the Hb structural switches follow specific combinatorial rules: studies with single amino acid modifications to the binding intermediates have revealed important symmetry/asymmetry features of the Hb tetramer's structural energetics . We plan to extend these studies using recombinant Hb's with designed combinations of altered residue sites for the O2 intermediates. Subunit interactions of the recombinant systems will be studied by techniques of hybridization, assembly and kinetics, as well as by direct O2 binding. Structural features will be analyzed by X-ray crystallography. The Hb regulatory system is an important prototype for a large family of cooperative multi-site regulatory assemblies. Thus the methods developed by this program should have wide applicability. Deeper understanding of human Hb mechanisms is also of current interest to the potential design of red cell substitute oxygen carriers and drug delivery systems.