NMR & FTIR SPEAR OF SELECTIVELY LAB TYROSINE & ASPARTIC ACID HEMOGLOBIN

SIR提供L-天冬氨酸(4-13C)、HOO*CCH_2CH(NH_2)COOH； 500毫克L-酪氨酸(苯酚-3，5-13C)，HOC6H4CH2CH(NH_2)COOH L-[环-“C6]酪氨酸；500毫克血红蛋白是a2/b2四聚体， 协同结合氧，在体内经历结构重排 这一过程。它在两个状态之间的变构转换是 被广泛接受，但血红蛋白行为的许多方面仍然存在 一个谜。其中一个未知数是玻尔粒子的具体机制。 在酸性条件下促进氧气释放的作用。 本提案描述了原位标记、核磁共振和核磁共振的应用 IR研究一种细菌的生化意义和性质 特定的氢键，已经被认为具有显著的 在血红蛋白的R到T转变中的作用，并可能有助于 玻尔效应。Tyra42和Asp B99在Alb2上的氢键 接口被认为是稳定T状态的关键 来自几个试验田的数据。基于紫外共振拉曼光谱 和未标记蛋白的红外光谱，表明Asp B99可能是 该对的氢键给体因此可能参与了玻尔效应。 对策略性标记的血红蛋白的实验应该允许准确的 待测定的氢键的组成。一旦确定了这一点， 可以进行pH依赖的研究来调查 特定残留物对酸度变化的反应。其他

The SIR provided L-Aspartic Acid (4- 13C) , HOO*CCH2CH(NH2)COOH; 500mg L-Tyrosine (phenol-3,5- 13C) , HOC6H4CH2CH(NH2)COOH; 500mg L-[RING-"C6]Tyrosine; 500mg Hemoglobin is an a2/b2 tetramer that cooperatively binds oxygen, undergoing a structural rearrangement in the process. Its allosteric transition between two states has been widely accepted, but many aspects of hemoglobin behavior still remain a mystery. Among the unknowns is the specific mechanism of the Bohr effect which promotes the release of oxygen under acidic conditions. This proposal describes the application of istopic labeling, NMR, and IR to investigate the biochemical significance and character of a specific hydrogen bond which has been suggested to have a significant role in the R to T transition in hemoglobin and may contribute to the Bohr effect. This H-bond between Tyra42 and Asp b99 at the alb2 interface is thought to be critical in stabilizing the T state based on data from several experimental fields. Based on UV resonance Raman and FIIR of unlabeled protein, it appears that Asp b99 may be the H-bond donor of the pair and thus, may be involved in the Bohr effect. Experiments on strategically labeled hemoglobin should allow the exact composition of the H-bond to be determined. Once this is determined, pH dependent studies could be conducted to investigate the behavior of specific residues in response to changes in acidity. Other