Editors' ChoiceChemistry

Vibrations Beyond the Active Site

Sci. Signal.  07 Jun 2011:
Vol. 4, Issue 176, pp. ec161
DOI: 10.1126/scisignal.4176ec161

Vibrational spectroscopy allows for probing the chemistry of enzymatic active sites with a time resolution roughly a millionfold higher than in nuclear magnetic resonance techniques. However, few studies have succeeded in applying vibrational probes to more global structural elucidation, encompassing secondary and tertiary organizational features. Remorino et al. used two-dimensional vibrational echo spectroscopy to uncover the structure of a tertiary contact in the helical dimer of an integrin protein that straddles the cell membrane. The method extracts geometries by measuring distance-dependent rates of vibrational energy transfer between isotopically labeled amino acid residues at specific sites in the peptide sequence.

A. Remorino, I. V. Korendovych, Y. Wu, W. F. DeGrado, R. M. Hochstrasser, Residue-specific vibrational echoes yield 3D structures of a transmembrane helix dimer. Science 332, 1206–1209 (2011). [Abstract] [Full Text]