Celiac-Related Properties of Chemically and Enzymatically Modified Gluten Proteins

Abstract

The effects of chemical (acid-heating treatment) and enzymatic (microbial transglutaminase, TGase) modification (deamidation) of gluten proteins on their physicochemical and celiac disease-related properties were studied. Ammonia release, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and sample solubility analyses were employed to check the extent of gluten modification. Among different treatments achieved, the acid-heating treatment performed at 90 degrees C for 3 h induced gluten deamidation, paralleling an increase of gluten solubility without relevant proteolysis. Changes in the immunoreactivity of celiac IgA anti-gliadin antibodies (AGAs) to modified gluten proteins were detected by using a competitive indirect enzyme-linked immunosorbent assay method. Chemical deamidation by acid-heating treatment of gluten lowered IgA-AGA immunoreactivity. IgA-AGA immunoreactivity to gliadins was increased when they were submitted to TGase-catalyzed deamidation. The acid-heating treatment of gluten reduced its cytotoxic activity on human colon adenocarcinoma LoVo cell line. These results showed that chemical deamidation of gluten may be envisaged as a way to lower the potential risk for celiac people due to widespread use of gluten as a food additive.

Effect of acetic acid deamidation‐induced modification on functional and nutritional properties and conformation of wheat gluten

“…Deconvolution of the amide I region of the samples revealed that they were composed of five components located at 1606, 1635, 1652, 1679 and 1697 cm −1 , representing intermolecular β-sheet of protein aggregation, extended β-sheet (hydrated), α-helix, β-turn and extended β-sheet respectively. 28 Table 2 shows that native wheat gluten contained 34.5% α-helix, 17.3% β-turn and 48.2% β-sheet, in agreement with the reports of Wang et al 29 and Berti et al, 14 and the changes in α-helix and β-sheet in the two modified samples from FTIR spectroscopy were in accordance with those of Raman spectroscopy (data not shown). A greater increase in both intermolecular β-sheet of protein aggregation and extended β-sheet was observed in H-DWG, while A-DWG showed a lower decrease in α-helix and a greater increase in β-turn.…”

Immunoreactivity of Antibodies Against Transglutaminase-Deamidated Gliadins in Adult Celiac Disease

“…IgA AGAs immunoreactivity to native and TG-treated gliadins was evaluated by means of a competitive indirect enzyme-linked immunosorbent assay (cELISA), based on gliadins (coated antigen) and human serum AGAs (primary antibody), as described by Berti et al [13]. The primary antibody was used in a 1:1 ratio with different concentrations of competitor (gliadin) solution (from 0.03 to 1,000 lg/mL).…”

Screening and statistical optimization of media ingredients for production of microbial transglutaminase

“…Applications of TGase for improvement of texture, water holding capacity, elasticity, nutritional value, and appearance of meat, fish, wheat and soybean products has been reported [6][7][8][9][10][11][12] . Modifications of physicochemical properties of dairy products and gluten for food applications and biomedical applications using TGase was reviewed [13][14][15] . MTGase have been reported in actinomycetes and bacteria such as Streptomyces mobaraensis 5,18 , S. ladakanum 16 , S. hygroscopicus 17 , Bacillus subtilis 19 and B. circulans 20 .…”