title: Antifreeze glycopeptide analogues: microwave-enhanced synthesis and functional studies.
abstract: Antifreeze glycoproteins enable life at temperatures below the freezing point of physiological solutions. They usually consist of the repetitive tripeptide unit (-Ala-Ala-Thr-) with the disaccharide alpha-D-galactosyl-(1-3)-beta-N-acetyl-D-galactosamine attached to each hydroxyl group of threonine. Monoglycosylated analogues have been synthesized from the corresponding monoglycosylated threonine building block by microwave-assisted solid phase peptide synthesis. This method allows the preparation of analogues containing sequence variations which are not accessible by other synthetic methods. As antifreeze glycoproteins consist of numerous isoforms they are difficult to obtain in pure form from natural sources. The synthetic peptides have been structurally analyzed by CD and NMR spectroscopy in proton exchange experiments revealing a structure as flexible as reported for the native peptides. Microphysical recrystallization tests show an ice structuring influence and ice growth inhibition depending on the concentration, chain length and sequence of the peptides.
authors.affiliation: Organic and Bioorganic Chemistry, Bielefeld University, Bielefeld, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Heggemann
authors.forename: Carsten
authors.initials: C
authors.lastname: Budke
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schomburg
authors.forename: Zsuzsa
authors.initials: Z
authors.lastname: Majer
authors.forename: Marco
authors.initials: M
authors.lastname: Wissbrock
authors.forename: Thomas
authors.initials: T
authors.lastname: Koop
authors.forename: Norbert
authors.initials: N
authors.lastname: Sewald
mesh_terms: D021301:Antifreeze Proteins / Q000138:chemical synthesis* / Q000737:chemistry*; D003460:Crystallization; D008872:Microwaves; D015394:Molecular Structure; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D021301:Antifreeze Proteins