ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Incorporation of β-(1,6)-linked glucooligosaccharides (pustulooligosaccharides) into plant cell wall structures

Zuzana Zemková, Soňa Garajová, Dana Flodrová, Pavel Řehulka, Ivan Zelko, Renáta Vadkertiová, Vladimír Farkaš, and Eva Stratilová

Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia

E-mail: chemevi@savba.sk

Abstract: Protein extract of germinating nasturtium (Tropaeolum majus) seeds containing xyloglucan endotransglycosylase (xyloglucan xyloglucosyl transferase, EC 2.4.1.207, abbreviated XET) exhibited the heterotransglycosylating activity with donor/acceptor substrate pair xyloglucan/sulphorhodamine labelled pustulooligosaccharides (XG/PUOS-SR) in a dot blot assay. The heterotransglycosylating activity was confirmed by the substrate-product changes during transglycosylation by HPLC size-exclusion chromatography. Another donor substrate capable of being coupled with PUOS-SR was cellulose, probably owing to its structural similarity to xyloglucan. Surprisingly, microscopic comparison of the incorporation of the labelled xyloglucan nonasaccharide XGO9-SR (specific substrate for XET) and PUOS-SR into the cell wall structures clearly showed differences in their binding to specific cell structures: the primary cell wall and the plasma membrane. These findings indicate the existence in nasturtium of XETs with different localisation, substrate specificity and, probably, function.

Keywords: xyloglucan endotransglycosylase – XET – heterotransglycosylation – cell wall – plasma membrane

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0167-x

Chemical Papers 66 (9) 814–820 (2012)