Monomeric gliadins

Ewart (1990) [10] criticized Shewry s classification, arguing that the polymeric glutenins are fundamentally different from the monomeric gliadins because of their intermolecular disulfide bonding capacity [11]. 

The first two reports on the use of flow FFF for separating wheat proteins appeared in the literature in 1996 when researchers firom two independent laboratories reported characterization of wheat proteins from different varieties extracted by different methods and analyzed on two different types of flow FFF apparatus. Wahlund et al. - used asymmetrical flow FFF to examine proteins extracted firom two bread wheat varieties of different protein content using sequential extraction with increasing concentrations of dilute hydrochloric acid (HCl). Stevenson and Preston used symmetrical flow FFF to examine proteins extracted firom Katepwa, a high quahty bread wheat variety, using a modification of the traditional Osborne extraction procedure. Results from both studies showed that for the monomeric gliadin-type fractions ranged in size from 8 to... 

Other workers used 0.1 m acetic acid for gluten separation then changed to dilute hydrochloric acid followed by neutralisation with sodium hydroxide.8 Byers et al. used 50% propan-l-ol in preference to 70% ethanol.9 Methods based on extraction with sodium dodecyl sulfate (SDS) have been developed by Danno10 as well as Graveland et al.11,12 Sonication of the SDS extract was introduced by Singh et al.13,14 Burnouf et al. introduced the use of dimethyl sulfoxide (DMSO) to remove monomeric proteins and a few small gliadins.15... 

The wheat storage proteins without interchain disulfide bonds are monomeric and are termed gliadins, those with interchain disulfide bonds are polymeric and are called glutenins. Gliadins plus glutenins form gluten. Originally, it was assumed that the toxicity for CD patients was restricted to... 

HMW MMW LMW Polymeric Monomeric Monomeric Polymeric HMW subunits of glutenins ai-Type gliadins a-Type and 7-type gliadins LMW subunits of glutenins HMW secalins ai-Secalins 40 K 7-secalins 75 K 7-secalins D-hordeins C-hordeins 7-Hordeins B-hordeins... 

The sulfur-rich prolamins are quantitatively the most abundant group in wheat, barley and rye, accounting for approximately 80-90% of total prolamin fractions. They include polymeric and monomeric components and consist of at two families in each species, the B- and y-hordeins of barley two types of y-secalin of rye and a, 3 and y-gliadins and LMW glutenin subunits of wheat. The sulfur-poor prolamins include C-hordeins of barley, (O-secalin of rye and co-gliadin of wheat. 

Gluten is a complex mixture of gliadins (monomeric gluten proteins) and glutenins (polymeric gluten proteins) comprise about 80% of the proteins present in wheat grain. 

Monomeric albumins and globulins are proteins that have molecular weights in the range of 20,000-30,000 and elute in a small peak at elution times slightly greater than the gliadins. 

Several approaches have been devised to separate the different groups in the complex mixture and to permit individual proteins or subunits to be identified and quantified. A two-step SDS-PAGE procedure was introduced by Singh and Shepherd (1988) in which the imreduced total protein is first loaded on the gel. The gliadins and other monomeric components are allowed to rim ahead of the polymeric components, which form a smear near the origin. The proteins from the smear are then removed and run under reducing conditions on SDS-PAGE. The result of this second step for a... 

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