[Study of Monomolecular layers of immunoglobulin G by IR-spectroscopy].

The deposited immunoglobulin G (IgG) monomolecular layers consisting of native protein molecules oriented either horizontally or vertically towards the Si internal reflection plate, and also of molecules, denatured in monolayers at air-water interface have been studied by attenuated total-reflection (ATR) IR-spectroscopy technique. It was shown that deposition of IgG molecules on Si surface from monolayers at air--water interface did not change conformation and orientation of the molecules. The value of monolayer thickness correlates with the IgG molecule dimensions calculated from X-ray diffraction data. It was also established that beta-conformation prevails in the secondary structure of both native and denaturated molecules.