WHEAT DOUGH EXTENSIBILITY SCREENING USING A 2-SITE ENZYME-LINKED-IMMUNOSORBENT-ASSAY (ELISA) WITH ANTIBODIES TO LOW-MOLECULAR-WEIGHT GLUTENIN SUBUNITS

The relationships between total glutenin subunit content, low molecula r weight glutenin subunit (LMW-GS) content, and dough extensibility we re examined with several sets of flours, in which the overall correlat ions between flour protein content and extensibility were poor, The po tential for monoclonal antibodies with specificities for various LMW-G S groups to screen for differences in dough extensibility was assessed using a two-sire (sandwich) enzyme-linked immunosorbent assay (ELISA) , following extraction of LMW-GS using 60% ethanol and 10mM dithiothre itol. A range of solid-phase bound (immobilized) antibodies with speci ficities for different LMW-GS were combined with two labeled (detectio n) antibodies: 21817, which bound a cluster or B-LMW-GS, and 23724, wh ich bound both low molecular weight glutenin subunits (HMW-GS) and B-L MW-GS. Significant correlations were obtained with each flour set usin g the more specific detection antibody, 21817, although the specificit y of the immobilized antibody was less important. Binding of the antib ody combinations that related to extensibility correlated with LMW-GS content measured using reversed-phase high-performance liquid chromato graphy (RP-HPLC). The antibody binding, RP-HPLC, and extensibility cor relations were of the order r = 0.4-0.7, which suggested that variatio n in total LMW-GS content accounted for only part of the variation in extensibility between flours. It is possible that interactions between several factors, including allelic composition of HMW-GS and LMW-GS a s well as total LMW-GS content may determine dough extensibility.