1 Department of Molecular Biology and Genetics - Afgrødegenetik og Bioteknologi, Department of Molecular Biology and Genetics, Science and Technology, Aarhus University2 Sektion for Bioteknologi3 Department of Molecular Biology and Genetics - Afgrødegenetik og Bioteknologi, Department of Molecular Biology and Genetics, Science and Technology, Aarhus University
Wheat (Triticum aestivum L.) possesses preformed phytase activity in the grain that is essential to make phosphate available to cell metabolism and in food and feed (Brejnholt S. et al., 2011). Cereals contain the purple acid phosphatase type of phytases, PAPhy (Dionisio G. et al., 2011a). Mature wheat grain is dominated by TaPAPhy_a which, after chromatographic purification, has been characterized by extensive peptide and glycopeptide sequencing by mass spectrometry. Seven N-linked glycosylation sites were found. Three of these sites were dominated by variant forms of the XylMan3FucGlcNAc2, i.e. the HRP-type of glycan. Complex-type glycans with one or two additional GlcNAc were observed, however in trace amount only. The mature protein is ca. 500 residues in size and appears to be truncated at the N- and C-termini (Dionisio G. et al., 2011b). References: Brejnholt S., Dionisio G., Glitsoe V., Skov L. Brinch-Pedersen H. (2011). The degradation of phytate by microbial and wheat phytases is dependent on the phytate matrix and the phytase origin. J. Sci. Food Agri. (in press). Dionisio G., Madsen C.K., Holm P.B., Welinder K.G., Jørgensen M., Stoger E., Arcalis E., Brinch-Pedersen H. (2011a) Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat (Triticum aestivum L.), Barley (Hordeum vulgare L.), Maize (Zea maize L.) and Rice (Oryza sativa L.). Plant Physiol. [in press, Jan 10, Epub ahead of print] Dionisio G., Brinch-Pedersen H., Welinder K.G., Jørgensen M. (2011b). Different site-specific N-glycan types in wheat (Triticum aestivum L.) PAP phytase. Phytochemistry (in press).