Lequin O, Albaret C, Bontems F, Spik G, Lallemand J Y
Départment de Chimie-Synthèse Organique, URA 1308 du CNRS, Ecole Polytechnique, Palaiseau, France.
Biochemistry. 1996 Jul 9;35(27):8870-80. doi: 10.1021/bi960022r.
The three-dimensional structure of bovine angiogenin has been determined using two- and three-dimensional proton NMR spectroscopy. The solution structure is very close to that recently determined by X-ray diffraction analysis. This structure appears well defined, even if five loops and one helix exhibit greater flexibility. Analysis of the active site geometry confirms the position of the Glu-118 residue which obstructs the pyrimidine binding site. There is no experimental evidence of an unobstructed conformation of angiogenin in solution. In addition, it appears that the Glu-118 and Ser-119 residues and the cell receptor binding loop may play an important role in the differences of C-terminal fragment organization and ribonucleolytic activity observed between angiogenins and ribonuclease A.
利用二维和三维质子核磁共振光谱法测定了牛血管生成素的三维结构。溶液结构与最近通过X射线衍射分析确定的结构非常接近。即使五个环和一个螺旋表现出更大的灵活性，该结构看起来也定义明确。活性位点几何结构分析证实了阻碍嘧啶结合位点的Glu-118残基的位置。没有实验证据表明血管生成素在溶液中有无障碍的构象。此外，Glu-118和Ser-119残基以及细胞受体结合环似乎在血管生成素和核糖核酸酶A之间观察到的C末端片段组织和核糖核酸酶活性差异中起重要作用。
