NUCLEAR MAGNETIC DIPOLE INTERACTIONS IN FIELD-ORIENTED PROTEINS - INFORMATION FOR STRUCTURE DETERMINATION IN SOLUTION

The measurement of dipolar contributions to the splitting of N-15 reso nances of H-1-N-15 amide pairs in multidimensional high-field NMR spec tra of field-oriented cyanometmyoglobin is reported. The splittings ap pear as small field dependent perturbations of normal scalar couplings . Assignment of more than 90 resonances to specific sequential sites i n the protein allows correlation of the dipolar contributions with pre dictions based on the known susceptibility and known structure of the protein. Implications as an additional source of information for prote in structure determination in solution are discussed.