FROZEN SOLUTION & VECTORIALLY ORIENTED SINGLE MONOLAYER OF MEMBRANE HEME PROTEIN

冷冻溶液

• 批准号: 6120381
• 负责人: J. KENT BLASIE
• 金额: --
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6120381
• 关键词: biomedical resource; enzymes; human tissue; spectrometry

Greatly improved polarized Fe-EXAFS data have been obtained from frozen-hydrated single monolayers of yeast cytochrome c covalently tethered to the nonpolar surface of mixed-CH3/-SH (6:1) endgroup Self-Assembled Monolayers (SAM) chemisorbed onto silicon substrates. These data have been analyzed utilizing the EXAFS spectra calculated using FEFF7 and either a) the local atomic environment within 5A of the Fe-atom in the yeast cytochrome c crystal structure as a function of the angle between the heme plane and the monolayer plane or b) the lcoal atomic environment within 5A of the Fe-atom as time-averaged over the last 300 picoseconds of a 1 nanosecond Molecular Dynamics computer simulation of the hydrated tethered cytochrome c/SAM system. Both approaches provide an angle between the heme plane and the monolayer plane in good agreement with independent results from the optical linear dichroism of the heme groups electronic transitions while the second approach best accounts for all of the features of the experimental polarized EXAFS data ?i.e. both peak positions in k (A-1) Hand peak shapes as opposed to primarily peak positions?. Examination Hof the unpolarized EXAFS spectra calculated from periodically sampled H?i.e., every 50 picoseconds? instantaneous configurations occurring Hover the 1 nanosecond Molecular Dynamics simulation indicated that the Hlocal atomic environment within 5A of the Fe-atom characteristic of Hthe frozen-hydrated isotropic aqueous solution of yeast cytochrome c Hoccurs repeatedly, but infrequently within the simulated hydrated Htethered cytochrome c/SAM system.

大大改善了极化Fe-EXAFS数据已获得从 冷冻水合的酵母细胞色素c单分子膜 连接到混合-CH 3/-SH（6：1）端基的非极性表面 自组装单层（SAM）化学吸附到硅衬底上。 这些数据已被分析利用EXAFS谱计算 a）在5A内的本地原子环境， 酵母细胞色素c晶体结构中的Fe原子作为函数 或B）血红素平面和单层平面之间的角度 lcoal原子环境内的铁原子作为时间平均的5A 在1纳秒分子动力学的最后300皮秒 水合束缚的细胞色素c/SAM系统的计算机模拟。 这两种方法都提供了血红素平面和血红素平面之间的角度。 单层平面与独立的结果， 血红素光学线性二色性s电子跃迁 而第二种方法最好地考虑了 实验极化EXAFS数据？即k（A-1）中的两个峰位置 手峰形状与主要峰位置相反？ 考试 霍夫的非偏振EXAFS谱计算周期性采样 H？H？也就是说，每50皮秒？ 瞬时构形出现 悬停1纳秒分子动力学模拟表明， Fe原子特性的5A范围内的H局域原子环境 酵母细胞色素的冷冻水合各向同性水溶液 c H重复发生，但在模拟的水合 细胞色素c/SAM系统。