Purification and characterization of HMW glutenin subunits encoded by chromosome 1B of durum wheat (Triticum durum)

Five HMW subunits encoded by chromosome 1B of durum wheat were purified and characterized with respect to their amino acid compositions and N-terminal amino acid sequences. The sequences determined for subunits 1By8 and 1By16 were identical to each other and to that previously reported for subunit 1By9 from bread wheat. In contrast, the sequences of the x-type subunits fell into two groups, 1Bx6 and 1Bx20 differing from 1Bx13 and also from 1Bx7, which is from bread wheat, in the deletion of a block of five residues. The sequences of the x-type subunits also differed from each other in single amino acid substitutions, in particular two cysteine residues were replaced by tyrosines in 1Bx20.