DIFFERENCES BETWEEN HUMAN AND PORCINE INSULIN INVESTIGATED BY LINEAR PREDICTION C-13 NMR

The linear prediction method was used to analyze the **1**3C NMR free induction decay signals of a series of insulins and insulin derivatives. The higher resolution provided by this method, as compared with the conventional Fourier transformation approach, revealed differences between the **1**3C NMR spectra of human and porcine insulins. This may indicate differences between the structures of these closely related proteins beyond the difference between their primary structures. Such differences have not been observed previously either in solution or in the crystal phase.