Related Experiment Video
Updated: Aug 6, 2026

LERLIC-MS/MS for In-depth Characterization and Quantification of Glutamine and Asparagine Deamidation in Shotgun Proteomics
Published on: April 9, 2017
Effects of enzymatic deamidation by protein-glutaminase on structure and functional properties of wheat gluten
Yie Hui Yong1, Shotaro Yamaguchi, Yasuki Matsumura
1Laboratory of Quality Analysis and Assessment, Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Japan.
Abstract:
Protein-glutaminase (PG) purified from Chryseobacterium proteolyticum was used to investigate its deamidation effects on wheat gluten. Water-insoluble gluten was able to be deamidated to the extent of deamidation degree (DD) 72% in 200 mM sodium phosphate buffer (pH 7) at 40 degrees C for 30 h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis exhibited an upper shift of gluten bands with only deamidation for 1.5-2.0 h (DD 35-45%) compared to the bands of nondeamidated gluten. Results of Fourier transform infrared analysis revealed alterations in secondary structure of gluten by PG deamidation. The assignment within amide I region showed decreases in both inter- (around 1695 cm(-1)) and intramolecular beta-sheets (around 1680 cm(-1)) by deamidation suggesting the deterioration of the aggregation ability of gluten molecules. Solubility and emulsification properties of gluten at pH 7 were improved by deamidation, while both properties at pH 3 were deteriorated by deamidation. Enzyme-linked immunosorbent assay identified that allergenicity of deamidated gluten as compared to the nondeamidated cohorts was decreased remarkably as the deamidation time was prolonged.
Related Concept Videos
Protein Denaturation
Protein Folding Quality Check in the RER
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Protein Glycosylation
Glycosylation occurs in...
Protein Folding
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...

