A-gliadins

Fig. 10. Backscattered Raman and ROA spectra in H2O of wheat glutenin T-A-l peptide (top pair) at pH 3.5, wheat A-gliadin (middle pair) at pH 3.5, and wheat ogliadin (bottom pair) at pH 2.6. 

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. 

G4. Gerrard, J. W., Marko, A. M., and Buchan, D., Glutamic acid derivatives in juvenile and adult celiac disease, 1. Plasma glutamic acid levels after a gliadin tolerance test. Can. Med. Assoc. J. 83, 1321-1323 (1960). 

Janatuinen et al. (2000) ( continuation of Janatuinen et al, 1995) Randomized controlled Same study population Serum from 92 CD subjects 52 in remission 26 oats/26 control 40 new Dx of CD 19 oats/21 control 6 months 12 months Mean 49.9 14.7 g/day Mean 46.6 13.3 g/day Yes N/A Gliadin and Ret Abs not significantly different between oats and controls No increase in IELs among subjects in remission with and without oats IELs decreased among new Dx subjects with and without oats Results strengthen the view that most subjects tolerated oats in the amounts of 50-70 g/day in an otherwise GFD... 

Anderson, O.D., Greene, F.C. 1997. The a-gliadin gene family. II. DNA and protein sequence variation, subfamily structure, and origins of pseudogenes. TheorAppl Genet 95 59-65. 

Picarelli, A., Di Tola, L., Sabbatella, M., Greco, L., Silano, R., De Vincenzi, M. 1999. 31 43 Amino acid sequence of the a-gliadin induces endomysial antibody production during in vitro challenge. Scand J Gastroenterol 34 1099-1102. 

Recognition of a dominant T-cell epitope of A-gliadin by IgA antibodies of patients with CD was also described in another study [184]. 

Cornell HJ. Amino acid composition of peptides remaining after in vitro digestion of a gliadin sub-fraction with duodenal mucosa from patients with coeliac disease. Clin Chim... 

Figure 2. Schematic of conformational structure and aggregate state of A-gliadin under various conditions (9)...

Figure 3. Transmission electron micrograph of A-gliadin microfibrils preparation negatively stained with uranyl (9)...

Alpha (a) gliadin found in wheat and other cereals, a peptide component of gluten. 

Figure 13.7 Schematic sequences of a typical a-gliadin, y-gliadin, LMW subunit of wheat, and a co-secalin of rye. The repeated sequences present in the gliadins, LMW subunits and (o-secalin are based on related motifs and are rich in proline and glutamine. The repeated sequences in the HMW subunits are not related to those present in the other proteins [12,21].

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