Conformational studies of wheat flour high relative molecular mass glutenin subunits by circular dichroism spectroscopy

Conformational studies of 1D x 2, 1B x 7, and 1D y 12 high relative molecular mass glutenin subunits, extracted from Alisei 1 flour, are reported. Circular dichroism (CD) spectroscopy is employed to study their conformational polymorphism induced by urea and by urea in the presence of 1% sodium dodecyl sulfate (SDS). The CD spectra indicate that SDS promotes ordered structures. The addition of urea to the SDS‐acetate solution of 1D x 2, 1B x 7, and 1D y 12 subunits eliminates the effect of SDS. Its addition to the acetate solution of proteins induces conformational transitions to form a poly‐ L ‐proline II‐like structure. All the changes induced by urea follow a multistep transition process that is typical of proteins consisting of different domains. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 65: 142–147, 2002