Magnetic non-equivalence and dynamic NMR of N-methylene protons in a Histamine-containing pseudopeptide: Alanyl-Glycyl-Histamine
作者:Bernard Henry、Patrick Gizzi、Jean-Jacques Delpuech
DOI:10.1016/j.tet.2015.06.079
日期:2015.9
to explore the potential of an additional feature of proton 1D-NMR for the study of the properties of peptides in aqueous solution, namely the magnetic non-equivalence of N-methylene protons in linear acyclic peptides induced by an asymmetric carbon atom located nearby. For this exploratory study, we have chosen an l-Alanyl terminal residue adjacent to a Glycyl residue, itself grafted to an optically
本研究的目的是探索质子1D-NMR的其他特征在研究水溶液中肽的性质方面的潜力,即由C诱导的线性无环肽中N-亚甲基质子的磁非等价性。不对称碳原子位于附近。对于该探索性研究,我们选择了一个与甘氨酰残基相邻的1-丙氨酰末端残基,该残基本身已嫁接到光学惰性的末端组胺单元上,即含组胺的假肽1-丙氨酰基-甘氨酰组胺(AGHA)。甘氨酰和组胺N的磁性非对等物的pH和温度依赖性亚甲基质子被建模为在探索的pH范围(pH -0.78至12)中发现的四个AGHA分子电离态BH 3,BH 2,BH,B的加权平均值。pK决定了形态曲线,碱和酸催化的质子交换速率以及酰胺键的pK。