[Effect of thiol reagents on the structure of mucus glycoproteins (mucins)]

The structure of both native mucins and subunits obtained by thiol reduction was studied by small-angle X-ray diffraction. X-ray pattern from the subunits significantly differs from that of the native mucins in the number, spacings and width of the reflections observed. Decrease in the number of the reflections and increase of their width pointed out that isolated subunits are less regular structure than the whole mucin molecule. This may be due to the two reasons: 1) conformation of the subunits in native molecule differs from that of in isolate state; 2) native mucin molecule is not a simple polymer, formed by the subunits.