title: Chemical synthesis of a synthetic analogue of the sialic acid-binding lectin siglec-7.
abstract: As a basis for the development of an artificial carbohydrate-binding lectin, we chemically synthesized a domain of siglec-7, a well-characterized sialic-acid-binding lectin. The full polypeptide (127 amino acids) was constructed by sequential native chemical ligation (NCL) of five peptide segments. Because of poor cysteine availability for NCL, cysteine residues were introduced at suitable ligation sites; these cysteine residues were alkylated in order to mimic native glutamine or asparagine residues, or converted to an alanine residue by desulfurization after NCL. After folding the full-length polypeptide, the sialic-acid-binding activity of the synthetic siglec-7 was clearly demonstrated by STD NMR and ELISA experiments. We succeeded in the synthesis of siglec-7 by installing three extra cysteine residues with side-chain modifications and found that these modifications did not affect the binding activity.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan).
authors.forename: Masayuki
authors.initials: M
authors.lastname: Izumi
authors.forename: Akihisa
authors.initials: A
authors.lastname: Otsuki
authors.forename: Mika
authors.initials: M
authors.lastname: Nishihara
authors.forename: Ryo
authors.initials: R
authors.lastname: Okamoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kajihara
mesh_terms: D000595:Amino Acid Sequence; D015214:Antigens, Differentiation, Myelomonocytic / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D037102:Lectins / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular
chemical_list: D015214:Antigens, Differentiation, Myelomonocytic; D037102:Lectins; C402206:SIGLEC7 protein, human
keywords: NMR spectroscopy; carbohydrates; cysteine; native chemical ligation; synthetic lectin