一个单一的基团控制了人体胆汁胆汁酸结合蛋白的连接位选择性
Gregory P Tochtrop1, Gregory T DeKoster, Douglas F Covey
1Contribution from the Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8231, St. Louis, MO 63110, USA.
Journal of the American Chemical Society
|September 2, 2004
概括
人体阴道胆汁酸结合蛋白 (I-BABP) 对特定胆汁盐具有选择性结合. 一个单一的基群差异在混合物存在时,决定了与不同的位点的排他性结合.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 蛋白质连接体的识别对于生物过程至关重要.
- 人体胆汁液胆汁酸结合蛋白 (I-BABP) 在体内与各种胆汁盐相互作用.
- 了解连接体化学变异性对结合的影响是必不可少的.
研究的目的:
- 调查I-BABP对葡萄糖醇酸 (GCA) 和葡萄糖氧醇酸 (GCDA) 的结合部位选择性.
- 阐明I-BABP对化学多样性胆盐的认可的结构和能量基础.
主要方法:
- 用同位素丰富的胆盐用于结合性研究.
- 采用了二维异核核核磁共振 (NMR) 光谱学.
- 分析了I-BABP与单个和混合胆汁盐连接体的结合行为.
主要成果:
- 当单独呈现时,I-BABP将GCA和GCDA结合到两个部位.
- 在等离子混合物中,GCDA只结合于位点1,而GCA结合于位点2.
- 这种选择性是由类固醇骨干上的C-12基组决定的.
结论:
- 基于微妙的化学差异,I-BABP对胆汁盐具有显著的位点选择性.
- 观察到的选择性主要是由能量因素驱动的,而不是硬质障碍.
- 这一发现为I-BABP-胆盐相互作用的特异性提供了洞察力.
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These groups modify specific amino acids in a protein.
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