title: Stereoselective synthesis of Arabidopsis CLAVATA3 (CLV3) glycopeptide, unique protein post-translational modifications of secreted peptide hormone in plant.
abstract: The unique hydroxylproline (Hyp)-linked O-glycan modification is a common process in hydroxyproline-rich glycoproteins (HRGPs). The modification occurs through post-translational hydroxylation at 4-position of proline residues some of which are followed by O-glycosylation at the resulting Hyp which is also found in some secreted peptide hormones such as CLAVATA3 (CLV3) of Arabidopsis thaliana plants. An active mature CLV3 is a tridecapeptide linked to β-L-Araf-(1→2)-β-L-Araf-(1→2)-β-L-Araf at a Hyp residue in the center of the peptide sequence such as Arg-Thr-Val-Hyp-Ser-Gly-Hyp(L-Arafn)-Asp-Pro-Leu-His-His-His (n = 3). We report here the synthesis of the secreted and modified CLV3 glycopeptide with all glycoforms (Araf0-3CLV3) of A. thaliana plants. A highly stereoselective β-arabinofuranosylation of Hyp derivatives as the key step of the synthesis of CLV3 glycopeptide was achieved by NAP ether-mediated IAD, which was effectively applied to the synthesis of oligoarabinosylated hydroxylproline [Hyp(L-Araf1-3)] derivatives. Fmoc-solid phase peptide synthesis was carried out using COMU as the coupling reagent for the introduction of [Hyp(L-Araf0-3)] derivatives as well as further elongation to the CLV3 glycopeptides.
authors.affiliation: ERATO, Japan Science and Technology Agency (JST), Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. yukito@riken.jp.
authors.forename: Sophon
authors.initials: S
authors.lastname: Kaeothip
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ishiwata
authors.forename: Yukishige
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry*; D029681:Arabidopsis Proteins / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D060327:Solid-Phase Synthesis Techniques / Q000379:methods
chemical_list: C118167:AT2G27250 protein, Arabidopsis; D029681:Arabidopsis Proteins; D010455:Peptides