EN
Membrane and tissue proteins in biological systems are diffi cult to be isolated and crystallized. In recent years, a low resolution technique, Fourier Transform Infrared (FTIR) spectroscopy, has been improved and proven to be a reliable tool to determine the secondary structure of proteins. Using this technique, it is possible to see protein bands directly from the spectra of tissues and membranes which allow us to obtain information about protein secondary structure. Generally the information is deduced by monitoring the amide I band, which is located between 1700–1600 cm-1. This band is the result of many overlapping individual peaks arising from different protein conformations, such as α-helix, β-sheet or turns. In the current study, using Neural Network (NN) method based on FTIR spectra [Severcan et al. (2004) Anal Biochem], the radiation, epilepsy and antioxidant-induced variations in the secondary structure of proteins in brain tissues and membranes were determined. The results showed that lipoic acid treatment revealed an unaltered protein secondary structure, while radiation caused a signifi cant increase in random coil structure and epilepsy led to a signifi cant decrease in β-sheet structure in rat brain tissue. This study confi rms that NN approach based on FTIR data is a fast and effective method to predict the secondary structure of proteins in different biological systems.