Proton NMR Chemical Shift Behavior of Hydrogen-Bonded Amide Proton of Glycine-Containing Peptides and Polypeptides as Studied by ab initio MO Calculation

• Main Authors: I. Ando, S. Kuroki, K. Yamauchi, S. Hori
• Format: Article
• Language: English
• Published: MDPI AG 2002-08-01
• Series: International Journal of Molecular Sciences
• Subjects: NMR chemical shift/ ab initio MO/ hydrogen bond/ peptides/ polypeptides/ glycine residue
• Online Access: http://www.mdpi.com/1422-0067/3/8/907/
• ISSN: 1422-0067

Abstract: NMR chemical shifts of the amide proton of a supermolecule, an Nmethylacetamide hydrogen-bonded with a formamide, were calculated as functions of hydrogen-bond length RN…O and hydrogen-bond angles by FPT-GIAO method within the framework of HF/STO 6-31++G(d,p) ab initio MO method. The calculations explained reasonably the experimental data reported previously that the isotropic proton chemical shifts move downfield with a decrease in RN…O. Further, the behavior of proton chemical shift tensor components depending on the hydrogen-bond length and hydrogen-bond angle was discussed.