纽带或子效应:酸如何运输和释放氧化
Marcelo A Martí1, Mariano C González Lebrero, Adrián E Roitberg
1Departamento de Química Inorgánica, Analítica, y Química Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria, Pab. 2, C1428EHA, Buenos Aires, Argentina. marcelo@qi.fcen.uba.ar
Journal of the American Chemical Society
|January 15, 2008
概括
尼特罗福林 (NP) 储存氧化 (NO) 并释放它以帮助昆虫食. 这项研究揭示了NP使用pH触发的子机制来释放NO,而不是改变键强度.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 昆虫学 昆虫学是一门学科.
背景情况:
- 吸血昆虫使用唾液蛋白质称为尼特洛福林 (NP) 来促进食.
- 氧化 (NO) 被NP储存和运输,NP释放它引起血管扩张并抑制宿主体的血液凝结.
- 假设NP释放NO是由于pH从昆虫唾液 (pH5.6) 到宿主组织 (pH7.4) 的pH转移引发的形状变化引起的NO.
研究的目的:
- 在不同的pH值下,研究NP4中NO释放的分子机制.
- 阐明构造动力学和海姆-NO相互作用在NP介导的NO输送中的作用.
主要方法:
- 用分子动力学 (MD) 模拟来研究在pH值5.6和7.4.4的NP4构造变化.
- 使用多个转向分子动力学来计算NO释放的自由能量概况.
- 混合量子力学/分子力学 (QM/MM) 技术分析了-NO结构和Fe-NO键强度.
主要成果:
- NO从NP4逃脱主要由NO迁移率的差异来决定,而不是Fe-NO债券强度的变化.
- 在低pH (5.6) 时,类似子的结构有效地捕获NO.
- 在更高的pH值 (7.4) 时,NP4的构造变化,打开子,促进NO的释放.
结论:
- NP4利用一种独特的子机制来释放NO,与其他血红蛋白中看到的连接键调节不同.
- 这种子的pH值依赖的打开和关闭控制了NO的捕获和输送.
- 这一发现为尼托福林如何促进昆虫的血液养提供了分子解释.
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