The conformation of porcine-brain natriuretic peptide by two-dimensional NMR spectroscopy

Two-dimensional (2D) 1H-NMR spectra of porcine-brain natriuretic peptide (pBNP) have been recorded at 300 MHz and 400 MHz. Peak assignments have been made and the combined information from chemical shifts, coupling constants, temperature coefficients and NOEs have been used to determine the conformational properties of pBNP in (C2H3)2SO. Overall the peptide appears to be flexible, with the possibility of some beta-type structure near the C terminus. Some of the assignments and deduced structural features in the current study differ from those in a recent report by Inooka et al. [Inooka, H., Kikuchi, T., Endo, S., Ishibashi, Y., Wakimasu, M. and Mizuta, E. (1990) Eur. J. Biochem. 193, 127-134] which may indicate the sensitivity of the structure of this peptide to differences in solution conditions.