Synthesis and accumulation of amylase-trypsin inhibitors and changes in carbohydrate profile during grain development of bread wheat (Triticum aestivum L.)

Abstract

Background Recent studies indicate that amylase-trypsin inhibitors (ATIs) and certain carbohydrates referred to as FODMAPs (fermentable oligo-, di-, monosaccharides and polyols) play an important role in promoting wheat sensitivity. Hitherto, no study has investigated the accumulation of ATIs during the development of the wheat caryopsis. We collected caryopses of common wheat cv. ‘Arnold’ at eight different grain developmental stages to study compositional changes in ATI and FODMAP content. Results The harvested caryopses were analysed for their size, protein and carbohydrate concentrations. ATIs were further characterized by MALDI-TOF MS, and their trypsin inhibition was evaluated by an enzymatic assay. The results showed that ATI accumulation started about 1 week after anthesis and subsequently increased steadily until physiological maturity. However, the biological activity of ATIs in terms of enzyme inhibition was not detectable before about 4 weeks after anthesis. Carbohydrate analysis revealed the abundance of short-chain fructans in early stages of grain development, whereas non-water-soluble carbohydrates increased during later developmental stages. Conclusions The results provide new insights into the complex metabolisms during grain filling and maturation, with particular emphasis on the ATI content as well as the inhibitory potential towards trypsin. The time lag between ATI accumulation and development of their biological activity is possibly attributed to the assembling of ATIs to dimers and tetramers, which seems to be crucial for their inhibitory potential.

Identifying the shortfalls of crude protein-reduced, wheat-based broiler diets

“…Amylase trypsin inhibitors were detected and quantified in a wide range of wheat cultivars via discovery proteomics and data mining by Bose et al. (2020) and the synthesis and accumulation of amylase-trypsin inhibitors during grain development of bread wheat has been documented by Call et al. (2021) .…”

Structure, Function and Protein Engineering of Cereal-Type Inhibitors Acting on Amylolytic Enzymes

“…In wheat the more prominent ones are 0.28 (monomeric), 0.19 and 0.53 (both homodimeric) (named based on electrophoretic mobility), CM1, CM2, CM3, CM16 and CM17 (all heterotetrameric) (for names and numbering see Rodriguez-Loperena et al, 1975;Carbonero and Garcia-Olmedo, 1999;Geisslitz et al, 2021). A time lag between ATI accumulation during wheat grain filling and detection of the biological activity suggested that assembly into dimers and tetramers determined the inhibitory potential (Call et al, 2021). Nineteen ATI isoforms from the wheat cultivar Butte 86 (Altenbach et al, 2011) and 33 proteoforms of ATIs across different bread wheat cultivars are reported (Bose et al, 2020;Geisslitz et al, 2021).…”

Screening of α-amylase/trypsin inhibitor activity in wheat, spelt and einkorn by high-performance thin-layer chromatography

“…One was the tandem mass spectrometric analysis of known ATIs to identify/quantify their amounts in cereal products. [16][17][18][19][20][21][22][23][24][25] The other approach was the screening of the ATI inhibitory potency via enzymatic assays followed by non-selective spectrophotometric detection. 7,23,24,26 However, mass spectrometry and enzymatic assays were rarely combined for an ideal matching, difficult to interpret, 24 and recently no correlation between ATI amount and inhibition potential was found.…”