[Possible mechanism of CO2 interaction with NAD-dependent malate dehydrogenase]

IR spectra of NAD-dependent malate dehydrogenase in the deuterium oxide solutions were studied in the absence of CO2 and at solution saturation with it. The presence of CO2 in the system results in weakening the absorption band intensity at 1650 cm-1 and in the appearance of the band at 1543 cm-1, which is explained by the formation of carbamates under conditions of the protein molecules free amino groups interaction with CO2.