lysosomal酶识别的分子基础:三维结构的阴离子依赖的曼诺6酸盐受体
D L Roberts1, D J Weix, N M Dahms
1Department of Biochemistry, Medical College of Wisconsin, Milwaukee 53226, USA.
Cell
|May 30, 1998
概括
阴离子依赖的曼诺-6酸盐受体 (CD-MPR) 将 lysosomal 酶引导到 lysosomes. 它的结构揭示了具有独特联结位点的二元体,解释了酶亲和力差异.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 细胞生物学 细胞生物学
背景情况:
- lysosomal 酸酶通过阴离子依赖的曼诺6酸盐受体 (CD-MPR) 和IGF-II/阴离子独立的曼诺6酸盐受体 (IGF-II/CI-MPR) 向 lysosomes.
- 这些受体属于P型动物学菌素家族,共享序列相似性.
研究的目的:
- 为了确定牛CD-MPR外细胞质域的三维结构.
- 阐明CD-MPR对 lysosomal酶的差异性结合亲和力的结构基础.
主要方法:
- 牛CD-MPR (残留物3-154) 功能形式的糖化缺陷的X射线晶体学复合与曼诺6-酸盐.
- 1.8 年的高分辨率结构分析.
主要成果:
- CD-MPR的细胞外质域结晶为二聚体.
- 每个单体采用一个九链平坦的β-桶折叠,类似于avidin.
- 双质体在联结位点之间表现出40 Å的距离.
结论:
- CD-MPR的二元结构为其对不同溶解体酶的不同亲和关系提供了结构基础.
- 这种结构洞察力有助于理解溶酶酶向机制.
相关概念视频
Lysosomal Hydrolases
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
Structure of Porins
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel precursors...


