Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustrasse 3, 14195 Berlin, Germany.
Nat Chem. 2017 Dec;9(12):1263-1268. doi: 10.1038/nchem.2821. Epub 2017 Jul 10.
The amino acid serine is known to form a very stable octamer that has properties that set it apart from serine complexes of different sizes or from complexes composed of other amino acids. For example, both singly protonated serine octamers and anionic octamers complexed with two halogen ions strongly prefer homochirality, even when assembled from racemic D,L mixtures. Consequently, the structures of these complexes are of great interest, but no acceptable candidates have so far been identified. Here, we investigate anionic serine octamers coordinated with two chloride ions using a novel technique coupling ion mobility spectrometry-mass spectrometry with infrared spectroscopy, in combination with theoretical calculations. The results allow the identification of a unique structure for (SerCl) that is highly symmetric, very stable and homochiral and whose calculated properties match those observed in experiments.
丝氨酸是已知的能够形成非常稳定的八聚体的氨基酸，其性质使其有别于不同大小的丝氨酸配合物或由其他氨基酸组成的配合物。例如，无论是单质子化丝氨酸八聚体还是与两个卤素离子配位的阴离子八聚体都强烈地偏爱手性，即使是由外消旋的 D,L 混合物组装而成的。因此，这些配合物的结构非常有趣，但迄今为止还没有找到合适的候选物。在这里，我们使用一种新的技术，将离子淌度质谱与红外光谱相结合，并结合理论计算，研究了与两个氯离子配位的阴离子丝氨酸八聚体。研究结果确定了(SerCl)的独特结构，其具有高度对称、非常稳定和手性的特点，其计算性质与实验中观察到的性质相匹配。
