Gliadins structural studies

Others have since used preparative RP-HPLC to purify gliadins for characterization and structural studies and to relate them to rheological and breadmaking properties [181-183]. Similarly, high- and low-MW glutenin subunits have been fractionated by preparative or semipreparative RP-HPLC [108,109,184-186]. Wieser et al. [102] give an excellent overview of the use of RP-HPLC for preparative and analytical characterization of gluten subunits. 

This chapter has reviewed the application of ROA to studies of unfolded proteins, an area of much current interest central to fundamental protein science and also to practical problems in areas as diverse as medicine and food science. Because the many discrete structure-sensitive bands present in protein ROA spectra, the technique provides a fresh perspective on the structure and behavior of unfolded proteins, and of unfolded sequences in proteins such as A-gliadin and prions which contain distinct structured and unstructured domains. It also provides new insight into the complexity of order in molten globule and reduced protein states, and of the more mobile sequences in fully folded proteins such as /1-lactoglobulin. With the promise of commercial ROA instruments becoming available in the near future, ROA should find many applications in protein science. Since many gene sequences code for natively unfolded proteins in addition to those coding for proteins with well-defined tertiary folds, both of which are equally accessible to ROA studies, ROA should find wide application in structural proteomics. 

From the unique amino acid composition of the gliadin proteins, one would expect a structure that is quite different from globular proteins. However, optical rotation studies have shown that the gliadin proteins possess compact tertiary structures similar to those of globular proteins (4,5). 

The study of gliadin related C-hordeins served as a model for understanding the structure of the other S-poor prolamins [26]. The co-gliadins are homologous to rye (O-secalins and barley C-hordeins. 

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