2D 1H NMR studies of monomeric insulin.

In order to establish the conditions required for the observation of monomeric insulin in solution, a series of proton nuclear magnetic resonance studies of insulin in a variety of solvents was undertaken. Optimal spectra were recorded in trifluoroethanol- water mixtures in a 1:2 ratio. Using the sequential assignment approach the proton nuclear magnetic resonance spectrum of insulin was then assigned. Aspects of the structure of monomeric insulin in solution have been determined using the observed NOE cross peaks and slow exchange protons.