Raman optical activity and conformation of structurally important groups in peptides and proteins

M. Kubáňová1, L. Bednárová2, P. Maloň2, V. Baumruk1

1Institute of Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, Prague 2, CZ-121 16, Czech Republic

2Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo nám 2, 166 10, Prague, Czech Republic



Raman optical activity (ROA) represents a modern spectroscopic technique that can be applied to a wide range of chiral molecules starting from small organic molecules up to complex biomolecular systems [1]. Among other things ROA provides information about solution structure of peptides and proteins [2]. The aim of this work was to determine the relationship between three-dimensional structure and Raman optical activity of disulphide and amide groups in peptides. Characteristic band patterns of the polyproline II conformation (left-handed 31-helix) were found in the ROA spectra of poly(Pro-Gly-Pro), oxytocin and hinge peptide linked to the antigen sequence. ROA signal in the S-S and C-S stretching region was observed in ROA spectra of model cyclodextrin compounds connected with disulphide bonds [3]. Positive ROA band in the S-S stretching region was found in the ROA spectrum of oxytocin (the peptide with one S-S bridge). According to the theoretical studies of model disulphides, positive ROA signal in this region indicates positive dihedral angle Cβ-S-S-Cβ. This result is in agreement with the crystal structure. We have also worked on extension of ROA measurements to the hydrogen stretching region (2500–3200 cm–1).



1.     L. D. Barron, L. Hecht, I. H. McColl, E. W. Blanch, Mol. Phys. 102 (2004), 731-744.

2.     L. D. Barron, E. W. Blanch, L. Hecht, Adv. Protein Chem. 62 (2002), 51-90.

3.     P. Maloň, L. Bednárová, M. Straka, L. Krejčí, L. Kumprecht, T. Kraus, M. Kubáňová, V. Baumruk, Chirality, (2010) accepted 2010.



The Grant Agency of the Czech Republic is acknowledged for the support (projects 203/07/1335 and P205/10/1276).