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.


IR probes of protein microenvironments: utility and potential for perturbation

R. Adhikary, J. Zimmermann, P.E. Dawson, F.E. Romesberg, ChemPhysChem (2014) 15:849-853.
pubpic2014adhikaryWe use IR spectroscopy to characterize nSH3 variants labeled with CN or N3 at five different positions. Like carbon-deuterium (C-D) bonds, CN and N3 can provide information about their surrounding protein environment, but unlike C-D, they tend to be perturbative and thus should be used with caution.


Experimental characterization of electrostatic and conformational heterogeneity in an SH3 domain

R. Adhikary, J. Zimmermann, J. Liu, P.E. Dawson, F.E. Romesberg, J. Phys. Chem. B, 117:13082-13089.
pubpic2013adhikaryWe use the IR absorptions of carbon-deuterium bonds site-selectively incorporated throughout the N-terminal SH3 domain from the murine adapter protein CrkII to characterize its different microenvironments with high spatial and temporal resolution.


Direct observation of structural heterogeneity in a β-sheet

M.E. Cremeens, J. Zimmermann, W. Yu, P.E. Dawson, F.E. Romesberg, J. Am. Chem. Soc. (2009) 131:5726-5727.
pubpic2009cremeensWe demonstrate that deuterium atoms incorporated at Cα backbone positions (Cα−D bonds) are sensitive to the local backbone structure. DFT calculations are used to predict that Cα−D bonds of glycine are sensitive to their local structure, with the absorptions red-shifted for an extended β-sheet relative to γ- and α-helix-like turns. These predictions are confirmed in glycine-deuterated variants of the N-terminal Src homology 3 (nSH3) domain protein.