ASSIGNMENT OF THE H-1 CHEMICAL-SHIFTS OF GLYCOGEN

Assignments of nearly all the H-1 chemical shifts of glycogen are made by 2-D H-1-H-1 homonuclear and C-13-H-1 heteronuclear COSY. We demonstrated that it is possible to obtain well-resolved 2-D n.m.r. spectra for a large molecule like glycogen. The seven nonequivalent protons of the glucose residues in the alpha-(1 --> 4)-linked chains, and of those at the nonreducing ends. were completely assigned. Distinct chemical shifts for H-1 and H-2 immediately adjacent to the alpha-(1 --> 6) bonds at the branch points were also determined. Several modifications of previous C-13 chemical shift assignments were made from the heteronuclear 2-D n.m.r. data.