Two-Dimensional Infrared Spectroscopy of Antiparallel β-Sheet Secondary Structure

Citations Over TimeTop 1% of 2004 papers

Abstract

We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of antiparallel beta-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein vibrational spectroscopy. 2D IR correlation spectra of the amide I region of poly-l-lysine, concanavalin A, ribonuclease A, and lysozyme show cross-peaks between the IR-active transitions that are characteristic of amide I couplings for polypeptides in antiparallel hydrogen-bonding registry. For poly-l-lysine, the 2D IR spectrum contains the eight-peak structure expected for two dominant vibrations of an extended, ordered antiparallel beta-sheet. In the proteins with antiparallel beta-sheets, interference effects between the diagonal and cross-peaks arising from the sheets, combined with diagonally elongated resonances from additional amide transitions, lead to a characteristic "Z"-shaped pattern for the amide I region in the 2D IR spectrum. We discuss in detail how the number of strands in the sheet, the local configurational disorder in the sheet, the delocalization of the vibrational excitation, and the angle between transition dipole moments affect the position, splitting, amplitude, and line shape of the cross-peaks and diagonal peaks.

Related Papers

• → Nanoscale Characterization of Parallel and Antiparallel β-Sheet Amyloid Beta 1–42 Aggregates(2022)41 cited
• → Influence of Strand Number on Antiparallel β-Sheet Stability in Designed Three- and Four-stranded β-Sheets(2003)50 cited
• → Simulation of the β‐ to α‐sheet transition results in a twisted sheet for antiparallel and an α‐nanotube for parallel strands: Implications for amyloid formation(2011)18 cited
• → Insights into the determinants of β‐sheet stability: 1H and 13C NMR conformational investigation of three‐stranded antiparallel β‐sheet‐forming peptides(2003)13 cited
• [Determination of the secondary structure of proteins from circular dichroism spectra. IV. Contribution of aromatic amino acid residues into circular dichroism spectra of proteins in the peptide region].(1986)