Evidence of an unusual N-H—N hydrogen bond in proteins

R. Adhikary, J. Zimmermann, J. Liu, R. Forrest, T. Janicki, P. Dawson, S. Corcelli, F.E. Romesberg, J. Am. Chem. Soc. (2014) 136:13474-13477.
pubpic2014adhikaryWe characterize the IR stretching frequencies of deuterated variants of proline and four proline residues of an Src homology 3 domain protein. CD stretching frequencies are shifted to lower energies due to hyperconjugation with Ni electron density, and along with DFT calculations, the data reveal that the Ni+1-H–Ni interactions constitute H-bonds that may play an important role in protein folding, structure, and function.