Infrared Spectrometer Laboratory
CNR-IBF Laboratory - Technological Transfer Project "Oil Olive Quality Control"
- POR Sicilia - Mis. 3.15-C
Laboratory directed by: Prof. Valeria Militello

IR spectroscopy allows to analyze the intrinsic vibrational modes of biological samples. The main investigated infrared zones are those of the Amide I and Amide II bands. Amide I band is due to an out of phase combination of the C=O and C–N stretching modes of amide groups. Generally, it has a composite profile consisting of several spectral components related to the different types of secondary structures. By performing kinetics at controlled temperature, the time evolution of its spectral components during thermal treatment is a probe of protein structural changes. In particular, it is possible to monitor the usual conversion of α-helical structures in β-sheets and the formation of β-aggregated structures as a consequence of the protein heating. Amide II band is predominantly associated with the N–H in-plane bending of the peptidic groups. Its time evolution gives information on the protein unfolding. In fact, its changes reveal the replacement of the hydrogens located in the core of the native protein when a heat-induced partial opening of the protein takes place; when H–D exchange occurs, a simultaneous increase of Amide II’ (N-D in plane bending) and decrease of Amide II is observed.

The IR spectrometer is also equipped with a cryostat allowing the study of the spectra of samples at cryogenic temperatures. The main technical features of the spectrometer are listed below.

This laboratory is integrated in MeSIAM - Regional Laboratory of CNISM