Stereoselective synthesis of Arabidopsis CLAVATA3 (CLV3) glycopeptide, unique protein post-translational modifications of secreted peptide hormone in plant
作者:Sophon Kaeothip、Akihiro Ishiwata、Yukishige Ito
DOI:10.1039/c3ob41212a
日期:——
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.
Synthesis of the Highly Glycosylated Hydrophilic Motif of Extensins
作者:Akihiro Ishiwata、Sophon Kaeothip、Yoichi Takeda、Yukishige Ito
DOI:10.1002/anie.201404904
日期:2014.9.8
stereoselective synthesis of one of the highlyglycosylatedmotifs, Ser(Galp1)‐Hyp(Araf4)‐Hyp(Araf4)‐Hyp(Araf3)‐Hyp(Araf1). The synthesis has been completed by the application of 2‐(naphthyl)methylether‐mediated intramolecular aglycon delivery to the stereoselective construction of the Ser(Galp1) and Hyp(Arafn) fragments as the key step, as well as Fmoc solid‐phase peptide synthesis for the backbone