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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.

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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.

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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.

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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.