STUDIES OF ALLELIC VARIANTS OF HIGH MOLECULAR WEIGHT GLUTENIN SUBUNITS BY REVERSED PHASE HIGH PERFORMACE LIQUID CHROMATOGRAPHY.

Allelic variants of high molecular weight (HMW) glutenin subunits, present at the three Glu-1 loci, have been characterised by reversed -phase high performance liquid chromatography (RP­HPLC). Subunits were analysed both in reduced and reduced and alkylated forms using 4-vinylpyridine . Differences in elution times, that were observed when the same subunit was either reduced or reduced and alkylated , clearly showed differential effects of alkylation on subunits encoded at the different loci present on the A-, B- or D-genome (homeoallelic subunits) and on x- or y-type subunits according to their different number of cysteine residue . Allelic subunits showing identical apparent molecular weight when separated on SDS-PAGE but different surface hydrophobicity are reported. In particular, RP-HPLC separation of HMW glutenin subunits present in the bread wheat cultivar Fiorello, which was reported to possess the recombinant pair 5 + 12 at the Glu-D1 locus, indicated that subunit 5 present in this cultivar was different in surface hydrophobicity from subunit 5 present in cultivars showing the pair 5 + 10. Possible implication for qualitative differences from the results obtained are discussed.