在气相中化谷氨酸和结构类型的结构和化度
Andrew S Lemoff1, Matthew F Bush, Chih-Che Wu
1Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Journal of the American Chemical Society
|July 21, 2005
概括
和离子以非zwitterionic形式与谷氨酸结合,与水分子相结合较弱. 这种结合结构得到了红外分离实验和理论计算的证实.
科学领域:
- 物理化学 物理化学
- 生物物理化学 生物物理化学
- 计算化学计算化学
背景情况:
- 像谷氨胺这样的氨基酸在生物系统中起着至关重要的作用.
- 了解与氨基酸的溶解和金属离子相互作用对生物化学至关重要.
- 之前的研究已经探索了金属离子与氨基酸衍生物的相互作用.
研究的目的:
- 为了研究酸和酸谷氨酸复合物的结构,有和没有水.
- 确定水分子与这些复合体的结合能.
- 阐明zwitterionic与非zwitterionic形式在金属离子复合中的作用.
主要方法:
- 黑体红外辐射解离 (BIRD) 实验被用来探测水损失.
- 应用总方程建模来确定值分离能量 (E(o)).
- 密度函数理论 (DFT) 的计算被用来建模复杂结构和能量学.
主要成果:
- 从酸和酸谷氨中失去水的值分离能量分别为63±1和53±1kJ/mol.
- 这些值表明这些金属复合体中的谷氨胺具有非zwitterionic结构.
- 发现水的结合能量低于zwitterionic形式,这表明非zwitterionic复杂化.
结论:
- 化和化谷氨酸主要采用非zwitterionic结构.
- 金属离子与氨基酸骨干和侧链氨基酸氧相协调.
- 与zwitterionic形式相比,水分子与这些非zwitterionic复合体的结合较弱.
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