人类长链乙-CoA脱酶和相关乙-CoA脱酶的扩展基质特异性的结构基础
Beena Narayanan1, Chuanwu Xia2, Ryan McAndrew1,3
1Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
Scientific reports
|June 5, 2024
概括
晶体结构显示,人类的长链乙-CoA脱酶 (LCAD) 结合了重的基质,这表明其作用超出了脂肪酸氧化. 这一发现将LCAD与ACAD10和ACAD11重新分类为一个不同的酶类.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 人类长链乙-CoA脱酶 (LCAD) 传统上以线粒体脂肪酸β-氧化而闻名.
- LCAD是一种同位四重体的黄蛋白,每个子单元含有一种FAD辅因子.
- 催化基被确定为Glu291.1.
研究的目的:
- 确定人类LCAD和一种催化不活跃的突变体 (Glu291Gln) 的晶体结构.
- 阐明LCAD基质特异性的结构基础.
- 探索LCAD超越脂肪酸代谢的潜在新功能.
主要方法:
- 使用X射线晶体学来确定三维结构.
- 致变酶被用来创建一个催化不活的Glu291Gln突变体.
- 结构分析的重点是基质结合腔和周围的残留物.
主要成果:
- 确定了野生类型和Glu291Gln突变人类LCAD的晶体结构.
- LCAD具有与其他乙-CoA脱酶不同的基质结合腔,可容纳较长和分支链基质.
- 一个涉及Pro132和相邻残留物的结构图案促进了像胆酸-CoA结合物这样的大型基质的结合.
- 这种基因在ACAD11和参与固醇代谢的细菌乙-CoA脱酶中保存着.
结论:
- LCAD表现出比以前认可的更广泛的基质特异性,包括固醇代谢物.
- 结构性发现表明LCAD,ACAD10和ACAD11代表了单独的真核细胞乙烯基-CoA脱酶类.
- LCAD的功能超越了线粒体β氧化,涉及到其它代谢途径.
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