title: Site-specific labeling of synthetic peptide using the chemoselective reaction between N-methoxyamino acid and isothiocyanate.
abstract: Site-specific labeling of synthetic peptides carrying N-methoxyglycine (MeOGly) by isothiocyanate is demonstrated. A nonapeptide having MeOGly at its N-terminus was synthesized by the solid-phase method and reacted with phenylisothiocyanate under various conditions. In acidic solution, the reaction specifically gave a peptide having phenylthiourea structure at its N-terminus, leaving side chain amino group intact. The synthetic human β-defensin-2 carrying MeOGly at its N-terminus or the side chain amino group of Lys(10) reacted with phenylisothiocyanate or fluorescein isothiocyanate also at the N-methoxyamino group under the same conditions, demonstrating that this method is generally useful for the site-specific labeling of linear synthetic peptides as well as disulfide-containing peptides.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hara
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Euis Maras
authors.initials: EM
authors.lastname: Purwati
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Tainosyo
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kawakami
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Hojo
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Saburo
authors.initials: S
authors.lastname: Aimoto
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D006801:Humans; D017879:Isothiocyanates / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D023083:beta-Defensins / Q000737:chemistry
chemical_list: D000596:Amino Acids; D017879:Isothiocyanates; D010455:Peptides; D023083:beta-Defensins; C037152:isothiocyanic acid
keywords: N-methoxyamino acid; human β-defensin; isothiocyanate; site-specific labeling