Fourier transform infrared attenuated total reflectance spectrometry of hemolymph and hemocyanin in water solutions

Fourier transform infrared (FT-IR) spectrometry with attenuated total refle ctance (ATR) was used for the determination of absorption and difference sp ectra of Rapana venosa hemolymph and of purified hemocyanin in solution or as lyophilized sample. In order to obtain a more detailed assignment of the protein spectra, the experiments were carried out both in water and in deu terium oxide solution. The results allowed to assign the protein spectra. T he amide bands were used to determine quantitatively the amount of the diff erent types of protein secondary structures. The analysis were carried out by using the spectral decomposition by Gaussian and Lorentzian functions, w hich permitted to obtain distinct peaks in the amide regions. Finally, by m easuring the areas of these peaks, the distribution of the secondary ordere d structures of IZ. venosa hemocyanin in solution and in solid was determin ed. (C) 1998 Elsevier Science B.V. All rights reserved.