Nara Masayuki, Morii Hisayuki, Tanokura Masaru
Department of Chemistry, College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Chiba, Japan.
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan.
Methods Mol Biol. 2019;1929:127-134. doi: 10.1007/978-1-4939-9030-6_9.
Fourier-transform infrared spectroscopy (FTIR) is a powerful tool for examining the metal coordination of the side chain COO groups of Glu and Asp on Ca-binding proteins in solution. The behavior of COO symmetric stretch can be investigated by using protein samples in HO solution. However, it is difficult to obtain information about the behavior of the COO antisymmetric stretch in HO solution, because the COO antisymmetric stretching band overlaps with the amide II band. Therefore, to obtain reliable infrared spectra in the region of COO antisymmetric stretch, exchangeable protons in the protein should be completely deuterated by incubating the apoprotein dissolved in DO under mild heating conditions.
傅里叶变换红外光谱（FTIR）是一种强大的工具，可用于研究溶液中钙结合蛋白上谷氨酸（Glu）和天冬氨酸（Asp）侧链羧基（COO）基团的金属配位情况。通过使用重水（D₂O）溶液中的蛋白质样品，可以研究羧基对称伸缩振动的行为。然而，在重水溶液中很难获得有关羧基反对称伸缩振动行为的信息，因为羧基反对称伸缩振动带与酰胺II带重叠。因此，为了在羧基反对称伸缩区域获得可靠的红外光谱，应通过在温和加热条件下孵育溶解于重水（D₂O）中的脱辅基蛋白，使蛋白质中的可交换质子完全氘代。
