摘要：

The nature of disulfide bonds in wheat glutenin and the factors that influence their formation were investigated by reducing and reoxidizing them under various conditions. The presence in glutenin of intramolecular disulfide bonds, as well as intermolecular, is indicated by a small viscosity increase that follows the large viscosity drop during glutenin reduction. Reoxidation of reduced glutenin in dilute solutions gave a low-molecular-weight product. Its formation indicated intramolecular disulfide bonds only. Reoxidation of reduced glutenin proceeded more slowly than that of reduced gliadin, which in a native state has primarily intramolecular disulfide bonds. Gliadin and glutenin may differ in polypeptide chain structure as demonstrated by starch-gel electrophoresis patterns of the reoxidized proteins. Reoxidation of reduced glutenin at 5% concentration gave a product that approached native glutenin in viscosity, molecular weight, and elasticity. Reoxidation either at higher concentrations or in urea yielded insoluble products. Appropriate ratios of intra- and intermolecular disulfide bonds are essential for viscoelastic properties of glutenin.

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