螺旋式二次结构的晶体学表征在阿尔法/贝塔中,其残留量为1:1的交替
Soo Hyuk Choi1, Ilia A Guzei, Lara C Spencer
1Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|April 29, 2008
概括
阿尔法/β-与交替的氨基酸形成螺旋结构. 结晶学数据显示,较长的受益于14/15螺旋,而不是11-螺旋,与NMR发现一致.
科学领域:
- 类化学 类化学
- 结构生物学 结构生物学
- 晶体学 晶体学是指结晶学.
背景情况:
- 具有交替残留的α/β酸采用螺旋式二次结构.
- β-残留物替代影响螺旋体类型和稳定性.
- 之前的NMR数据表明,具有环约束的β残留物促进了明显的α/β螺旋.
研究的目的:
- 提供11-螺旋和/或14/15-螺旋形成的α/β-的结晶学数据.
- 根据残留物成分和长度,研究alpha/beta-peptides的结构偏好.
- 为了将固态结构与溶液态NMR数据相关联.
主要方法:
- 使用X射线结晶学来确定14个α/β的结构.
- 用 (S,S) - 转2-氨基cyclopentanecarboxylic 酸 (ACPC) 的β-残留物和α-aminoisobutyric 酸 (Aib) 或L-alanine (Ala) 的α-残留物合成了.
- 的长度在4至10个残留物之间.
主要成果:
- 九种在固态中采用了11-螺旋 (i,i+3键).
- 三种酸采用了14/15螺旋 (i,i+4键).
- 两种体表现出混合结模式 (i,i+3和i,i+4),而3种结构之前未被描述.
结论:
- 结晶学数据证实了α/β中11-螺旋和14/15-螺旋结构的存在.
- 较长的α/β似乎优先采用14/15螺旋.
- 这些发现与之前关于α/β-构造的溶液状态NMR研究一致,并扩展了这些研究.
相关概念视频
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