title: Simultaneous lipidation of a characterized peptide mixture by chemoselective ligation.
abstract: The modification of a peptide antigen by a fatty acid such as palmitic acid is now recognized as a mean to induce cellular responses. Mixtures of lipopeptides, obtained by combining individually synthesized compounds, were shown to be promising synthetic vaccine candidates. Usually, in lipopeptide synthesis, the fatty acyl moiety is introduced on the crude peptide chain using solid-phase methods. The separation of the target compound from impurities by RP-HPLC is often complicated by the amphiphilic properties of lipopeptides and results in low overall yields. To overcome the difficulties associated with lipopeptide synthesis and mixture preparation, we have developed a method where the fatty acyl moiety is site-specifically and collectively introduced in solution onto a mixture of individually prepurified peptides. The lipidation is based on the quasistoichiometric and high-yielding ligation of a glyoxylyl lipid with hydrazinoacetyl peptides. The hydrazone constructs were prepared in a salt-free medium and could be isolated by direct lyophilization of the reaction mixture. This process is compatible with cysteinyl peptides, and no aggregation nor degradation could be observed.
authors.affiliation: UMR 8525 CNRS-Université de Lille 2-Institut Pasteur de Lille, Institut de Biologie de Lille, 1 rue du Pr. Calmette, BP 245, France. line.bourel@ibl.fr
authors.forename: Line
authors.initials: L
authors.lastname: Bourel-Bonnet
authors.forename: Dominique
authors.initials: D
authors.lastname: Bonnet
authors.forename: Frédéric
authors.initials: F
authors.lastname: Malingue
authors.forename: Hélène
authors.initials: H
authors.lastname: Gras-Masse
authors.forename: Oleg
authors.initials: O
authors.lastname: Melnyk
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry; D006835:Hydrazones / Q000737:chemistry; D007202:Indicators and Reagents; D008024:Ligands; D008055:Lipids / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D015302:Simian Immunodeficiency Virus / Q000737:chemistry
chemical_list: D006835:Hydrazones; D007202:Indicators and Reagents; D008024:Ligands; D008055:Lipids; D010455:Peptides; D003545:Cysteine