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A. Domínguez-Vidal, M.J. Ayora-Cañada, B. Lendl:
"DETECTION OF ALBUMIN UNFOLDING PRECEDING PROTEOLYSIS BY MEANS OF FT-IR SPECTROSCOPY USING 2D-CoS AND MCR";
Poster: ICAVS 4, Corfu; 10.06.2007 - 15.06.2007.

The combination of Fourier transform infrared (FT-IR) spectroscopy with appropriate data evaluation methods is an effective method for analyzing the secondary structure of proteins. The specific stretching and bending vibrations of the peptide backbone in amide I, II, and III bands provide information about the different types of secondary structure, since these vibrational modes are sensitive to hydrogen bonding and coupling between transition dipole of adjacent peptide bonds.
The hydrolysis of bovine serum albumin with protease K at 60 ºC has been studied by means of FT-IR. Two Dimensional Correlation Spectroscopy (2DCoS) has been used to study spectral changes during the reaction. The use of Multivariate Curve Resolution-Alternating Least Squares method applied to infrared measurements allowed the recovery of pure infrared spectra and concentration profiles of the different species involved in the reaction. Special attention was paid to the careful inspection of residuals again using 2DCoS. In this way, a heat-induced unfolding step previous to protein hydrolysis was identified. The infrared spectra of the intermediate species showed a more disordered structure than native albumin, being especially noticeable the decrease in -helix conformation. The formation of -sheet aggregates due to heating was detected too.

http://publik.tuwien.ac.at/files/pub-tch_8364.ppt