Proton nuclear magnetic resonance study of a selectively deuterated mouse monoclonal antibody: use of two-dimensional homonuclear Hartmann-Hahn spectroscopy

A 1H NMR study of a selectively deuterated mouse anti-dansyl monoclonal antibody is reported. Two-dimensional homonuclear Hartmann-Hahn (2D-HOHAHA) spectroscopy was found to be effective for establishing the connectivity between the C2-H and C4-H protons of His residues in the antibody molecule. It has been concluded that 1) even in the case of large proteins such as an antibody, HOHAHA peaks can be observed for amino acid residues that are located in a flexible environment, and 2) deuterium labeling is effective in reducing the efficiency of spin relaxation and makes it possible to increase the number of observed HOHAHA cross peaks. It was suggested that 2D-HOHAHA can also be used to obtain information concerning the flexible parts of antibody molecules.