pr5b00187_si_001.pdf (119.12 kB)
Proteomic Profiling of 16 Cereal Grains and the Application of Targeted Proteomics To Detect Wheat Contamination
journal contribution
posted on 2015-06-05, 00:00 authored by Michelle L. Colgrave, Hareshwar Goswami, Keren Byrne, Malcolm Blundell, Crispin
A. Howitt, Gregory J. TannerGlobal
proteomic analysis utilizing SDS-PAGE, Western blotting
and LC–MS/MS of total protein and gluten-enriched extracts
derived from 16 economically important cereals was undertaken, providing
a foundation for the development of MS-based quantitative methodologies
that would enable the detection of wheat contamination in foods. The
number of proteins identified in each grain correlated with the number
of entries in publicly available databases, highlighting the importance
of continued advances in genome sequencing to facilitate accurate
protein identification. Subsequently, candidate wheat-specific peptide
markers were evaluated by multiple-reaction monitoring MS. The selected
markers were unique to wheat, yet present in a wide range of wheat
varieties that represent up to 80% of the bread wheat genome. The
final analytical method was rapid (15 min) and robust (CV < 10%),
showed linearity (R2 > 0.98) spanning
over 3 orders of magnitude, and was highly selective and sensitive
with detection down to 15 mg/kg in intentionally contaminated soy
flour. Furthermore, application of this technology revealed wheat
contamination in commercially sourced flours, including rye, millet,
oats, sorghum, buckwheat and three varieties of soy.