tailieunhanh - Báo cáo khoa học: Structural analysis ofN-glycans of the planarian Dugesia japonica.

To investigate the relationship between phylogeny and glycan structures, we analyzed the structure of planarianN-glycans. The planarian Duge-sia japonica, a member of the flatworm family, is a lower metazoan. N-gly-cans were prepared from whole worms by hydrazinolysis, followed by tagging with the fluorophore 2-aminopyridine at their reducing end. | 1FEBS Journal Structural analysis of N-glycans of the planarian Dugesia japonica Shunji Natsuka1 2 Yukiko Hirohata2 Shin-ichi Nakakita3 Wataru Sumiyoshi3 and Sumihiro Hase2 1 Department of Biology Faculty of Science Niigata University Japan 2 Department of Chemistry Graduate Schoolof Science Osaka University Japan 3 Life Science Research Center Kagawa University Japan Keywords diversity methylation N-glycans phylogeny planarian Correspondence S. Natsuka Department of Biology Faculty of Science Niigata University Niigata 950-2181 Japan Tel Fax 81 25 262 6174 E-mail natsuka@ Received 13 August 2010 revised 15 November 2010 accepted 17 November 2010 doi To investigate the relationship between phylogeny and glycan structures we analyzed the structure of planarian N-glycans. The planarian Duge-sia japonica a member of the flatworm family is a lower metazoan. N-gly-cans were prepared from whole worms by hydrazinolysis followed by tagging with the fluorophore 2-aminopyridine at their reducing end. The labeled N-glycans were purified and separated by three HPLC steps. By comparison with standard pyridylaminated N-glycans it was shown that the N-glycans of planarian include high mannose-type and pauci-mannose-type glycans. However many of the major N-glycans from planarians have novel structures as their elution positions did not match those of the standard glycans. The results of mass spectrometry and sugar component analyses indicated that these glycans include methyl mannoses and that the most probable linkage was 3-ơ-methylation. Furthermore the methyl residues on the most abundant glycan may be attached to the non-reducing-end mannose as the glycans were resistant to a-mannosidase digestion. These results indicate that methylated high-mannose-type glycans are the most abundant structure in planarians. Introduction The structures of N-glycans are generally diverse but the variation in diversity across the phylogeny