Monomeric wheat proteins

The use of symmetrical flow FFF hyphenated with RI and MALLS detectors to assess the size and shape of sequentially dilute HAc extracted monomeric rich and sonicated HAc extracted polymeric rich wheat proteins was reported by Stevenson et al. - values at peak for the monomeric extract varied from 31,000 to 33,000 and increased to approximately 110,0(X) at later elution times. Results for all five varieties of wheat included in this study were similar for the monomeric wheat protein extracts. The profiles of polymeric extracts for the five wheat samples ranged from 225,000 to 300,000 at peak and increased to approximately 7x10 after 60 min of elution as shown in Fig. 2. values for the polymeric protein fraction showed relatively small changes with increasing elution time (M ), suggesting that the larger polymeric proteins tend toward a more compact structure than the lower polymeric proteins. 

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. 

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... 

Feruloyl esterase activity was first detected in culture filtrates of Strepto-myces olivochromogenes (49), and has thereafter also been reported for some hemicellulolytic fungi (Table III). A partially purified feruloyl esterase from S. commune liberated hardly any ferulic acid without the presence of xylanase (65). Very recently a feruloyl esterase was purified from Aspergillus oryzae (Tenkanen, M. Schuseil, J. Puls, J. Poutanen, K., /. Biotechnol, in press). The enzyme is an acidic monomeric protein having an isoelectric point of 3.6 and a molecular weight of 30 kDa. It has wide substrate specificity, liberating ferulic, p-coumaric, and acetic acids from steam-extracted wheat straw arabinoxylan. 

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... 

Fu, B. X., and H. D. Sapirstein. 1996. Procedure for isolating monomeric proteins and polymeric glutenin of wheat flour. Cereal Chemistry 73 143-152. 

Silano, V., and Zahnley, J. C. (1978). Association o Tenebrio molitor L. -amylase with two protein inhibitors—one monomeric, one dimeric—from wheat flour. Differential scanning calorimetric comparison of heat stabilities. Biochim. Biophys. Acta 533, 181-185. 

---