Abstract
Proteome analyses were carried out on commercial wheat germ of mature grain from the biscuit-making wheat cultivar, Rosella. Wheat germ protein extracts were fractionated by two-dimensional gel electrophoresis across two different immobilised pH gradients: pH 4.0–7.0 and 6.0–9.0. A total of 612 individual protein spots were excised from the gels and characterised by peptide mass fingerprinting. From these analyses, 347 individual proteins were identified from protein sequence database interrogation, and 301 different types of protein were catalogued according to protein function. The remaining 265 protein spots gave poor or no matches to proteins in the databases and were not identified in this study. Six different classes of enzymes were identified in the germ, many of them having roles in the mobilisation of energy reserves for germination. Abundantly expressed enzyme classes include the oxidoreductases, transferases and hydrolases. A comparison was also made between the major protein classes expressed in the germ and protein classes expressed in the endosperm from previous proteomic work. This study contributes significantly to our knowledge of protein expression and heterogeneity in the germ of wheat grain and forms the basis for future studies in regard to the characterisation of proteins during the initial stages of germination.
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Abbreviations
- AcN:
-
Acetonitrile
- 2-DE:
-
two-dimensional gel electrophoresis
- IEF:
-
isoelectric focussing
- IPG:
-
immobilised pH gradient
- MALDI-TOF:
-
matrix-assisted laser desorption/ionisation-time of flight
- PMF:
-
peptide mass fingerprinting
- SDS-PAGE:
-
sodium dodecyl sulphate–polyacrylamide gel electrophoresis
- TBP:
-
tributyl phosphine
- TCA:
-
trichloroacetic acid
- TFA:
-
trifluoroacetic acid
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Acknowledgements
This research has been facilitated by access to the Australian Proteome Analysis Facility (APAF) established under the Australian Government’s Major National Research Facilities Program. This study was largely funded by the Value Added Wheat CRC, and Yunxian Mak is the recipient of a Value Added Wheat CRC Post-Graduate Scholarship.
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Mak, Y., Skylas, D.J., Willows, R. et al. A proteomic approach to the identification and characterisation of protein composition in wheat germ. Funct Integr Genomics 6, 322–337 (2006). https://doi.org/10.1007/s10142-005-0018-8
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DOI: https://doi.org/10.1007/s10142-005-0018-8