title: Microwave-assisted solid-phase synthesis of antifreeze glycopeptides.
abstract: 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 (syAFGPs, H-[Ala-Thr(Galβ1,3GalNAcα1→)-Ala]n -OH, n=2-6). By employing novel AFGP analogues, we have demonstrated that of the monodispersed syAFGPn (n=2-6, degree of polymerization, DP=2-6, Mw =1257-3690 Da), syAFGP5 (DP=5, Mw =3082 Da) and syAFGP6 (DP=6, Mw =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 syAFGP6 forms a typical poly-L-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.
authors: Field of Drug Discovery Research, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan.
authors: Ryukou
authors: R
authors: Izumi
authors: Takahiko
authors: T
authors: Matsushita
authors: Naoki
authors: N
authors: Fujitani
authors: Kentaro
authors: K
authors: Naruchi
authors: Hiroki
authors: H
authors: Shimizu
authors: Sakae
authors: S
authors: Tsuda
authors: Hiroshi
authors: H
authors: Hinou
authors: Shin-Ichiro
authors: S
authors: Nishimura
mesh_terms: D000595:Amino Acid Sequence; D021301:Antifreeze Proteins / Q000138:chemical synthesis* / Q000737:chemistry; D002942:Circular Dichroism; D008872:Microwaves; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D060327:Solid-Phase Synthesis Techniques / Q000379:methods*
chemical_list: D021301:Antifreeze Proteins