Reisdorf C, Abergel D, Bontems F, Lallemand J Y, Decottignies J P, Spik G
Laboratoire de Résonance Magnétique Nucléaire, Département de Chimie-Synthèse Organique, Ecole Polytechnique, France, Palaiseau.
Eur J Biochem. 1994 Sep 15;224(3):811-22. doi: 10.1111/j.1432-1033.1994.00811.x.
Angiogenins are 14-kDa proteins able to induce blood vessel growth in various preparations and are thus thought to be involved in the development of solid tumors. Angiogenins have significant similarities with extracellular ribonuclease and possess a characteristic nuclease activity against large RNA molecules. These proteins are also able to induce second-messenger pathways. We have undertaken the determination of the three-dimensional structure of bovine angiogenin by using nuclear magnetic resonance (NMR) spectroscopy. Since this protein was directly purified from cow milk, it was not possible to enrich angiogenin with 13C or 15N isotopes. However, extensive use of two-dimensional and three-dimensional proton NMR experiments enabled us to identify all but four spin systems and to assign all corresponding proton resonances. Identification of most backbone-backbone nuclear Overhauser enhancements led to the characterization of the secondary structure elements of the protein. Comparison with the structure of ribonuclease A and analysis of the location of conserved residues confirmed that the two molecules have very similar structures.
血管生成素是一种14千道尔顿的蛋白质，能够在多种制剂中诱导血管生长，因此被认为与实体瘤的发展有关。血管生成素与细胞外核糖核酸酶有显著的相似性，并对大的RNA分子具有独特的核酸酶活性。这些蛋白质还能够诱导第二信使途径。我们利用核磁共振（NMR）光谱法测定了牛血管生成素的三维结构。由于这种蛋白质是直接从牛奶中纯化出来的，因此无法用13C或15N同位素富集血管生成素。然而，广泛使用二维和三维质子核磁共振实验使我们能够识别除四个自旋系统外的所有自旋系统，并确定所有相应的质子共振。大多数主链-主链核Overhauser增强效应的识别导致了该蛋白质二级结构元件的表征。与核糖核酸酶A的结构比较以及对保守残基位置的分析证实，这两种分子具有非常相似的结构。
