Microwave‐Assisted Solid‐Phase Synthesis of Antifreeze Glycopeptides. Issue 12 (10th February 2013)

• Record Type: Journal Article
• Authors: Izumi, Ryukou; Matsushita, Takahiko; Fujitani, Naoki; Naruchi, Kentaro; Shimizu, Hiroki; Tsuda, Sakae; Hinou, Hiroshi; Nishimura, Shin‐Ichiro
• Is Part Of: Chemistry. Volume 19:Issue 12(2013)
• Page Start: 3913
• Page End: 3920
• Publication Date: 2013-02-10
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201203731
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Microwave‐assisted solid‐phase synthesis allows for the rapid and large‐scale preparation and structure–activity characterization of tandem repeating glycopeptides, namely monodispersed synthetic antifreeze glycopeptides (<italic>sy</italic>AFGPs, H‐[Ala‐Thr(Galβ1, 3GalNAcα1→)‐Ala]_{<italic>n</italic>}‐OH, <italic>n</italic>=2–6). By employing novel AFGP analogues, we have demonstrated that of the monodispersed <italic>sy</italic>AFGP_{<italic>n</italic>} (<italic>n</italic>=2–6, degree of polymerization, DP=2–6, <italic>M</italic>_w=1257–3690 Da), <italic>sy</italic>AFGP₅ (DP=5, <italic>M</italic>_w=3082 Da) and <italic>sy</italic>AFGP₆ (DP=6, <italic>M</italic>_w=3690 Da) exhibit the ability to form typical hexagonal bipyramidal ice crystals and satisfactory thermal hysteresis activity. Structural characterization by NMR and CD spectroscopy revealed that <italic>sy</italic>AFGP₆ forms a typical poly‐<sc>L</sc>‐proline type II helix‐like structure in aqueous solution whereas enzymatic modification by sialic acid of the residues at the C‐3 positions of the nonreducing Gal residues disturbs this conformation and eliminates the antifreeze activity.</p> </abstract>