Grupo de Espectrocopía Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico UVa, Universidad de Valladolid, 47011, Valladolid, Spain.
Angew Chem Int Ed Engl. 2019 Nov 4;58(45):16002-16007. doi: 10.1002/anie.201907222. Epub 2019 Oct 1.
Neutral glutamine has been evaporated by laser ablation of its solid sample to seed a rare gas carrier prior to a supersonic expansion and proved by Fourier transform microwave techniques. We report on three distinct neutral conformers that show a singular non-interacting and flexible amide sidechain in contrast with the other proteinogenic aliphatic amino acids. It could explain the essential biological role of glutamine as a nitrogen source, and its unique ability to form a variety of hydrogen bonds with peptide backbones. Common computational methods fail to predict the delicate balance of intramolecular interactions controlling the geometry of the most stable conformer. The spectroscopic data here reported can be used to benchmark novel computational methods in quantum chemistry.
采用激光烧蚀其固态样品蒸发中性谷氨酰胺，在超音速膨胀之前将其作为稀有气体载体，并通过傅里叶变换微波技术进行了验证。我们报告了三种不同的中性构象体，它们表现出独特的非相互作用和灵活的酰胺侧链，与其他蛋白质源的脂肪族氨基酸形成对比。这可以解释谷氨酰胺作为氮源的基本生物学作用，以及其与肽骨架形成多种氢键的独特能力。常见的计算方法无法预测控制最稳定构象体几何形状的分子内相互作用的微妙平衡。这里报道的光谱数据可用于基准量子化学中的新型计算方法。
