Sulfhydryl and Disulfide Groups in Glycinin. The Major Soybean Protein.

摘要

The number of disulfide (SS) bonds in Glycinin-the major soybean protein-and their rate of cleavage by dithiothreitol (DTT) were determined at various concentrations of urea. A progressive increase in SS bond scission was observed with increasing urea concentration reaching the maximum of 20 SS bonds at 8M urea. In addition, a linear relationship was obtained for the rate of SS cleavage as a function of urea concentration. These results indicate that most of the disulfide bridges are buried in the interior of the protein molecule. Upon exposure to alkaline denaturation, a maximum of 9.2 sulfhydryl (SH) groups were obtained per mole of glycinin at pH 11.9.