title: Characterization of N-terminal structure of TLR2-activating lipoprotein in Staphylococcus aureus.
abstract: Staphylococcus aureus is known to activate mammalian immune cells through Toll-like receptor 2 (TLR2). We recently demonstrated that a lipoprotein fraction obtained from S. aureus by Triton X-114 phase partitioning is a potent activator of TLR2. In this study, we separated TLR2-activating lipoproteins expressed in S. aureus and characterized an N-terminal structure. The lipoprotein fraction of S. aureus was prepared by glass bead disruption followed by Triton X-114 phase partitioning. The TLR2-activating molecules were mainly detected in the mass range of 30-35 kDa. Seven lipoproteins were identified by the mass spectra of their tryptic digests. Among them, three lipoproteins were separated by preparative SDS-PAGE and proved to activate TLR2. After digestion with trypsin in the presence of sodium deoxycholate, the N terminus of the lipopeptide was isolated from lipoprotein SAOUHSC_02699 by normal phase high pressure liquid chromatography and characterized as an S-(diacyloxypropyl)cystein-containing peptide using tandem mass spectra. The synthetic lipopeptide counterpart also stimulated the cells via TLR2. These results showed that the diacylated lipoprotein from S. aureus acts as a TLR2 ligand in mammalian cells.
authors.affiliation: Department of Nanostructure and Advanced Materials, Kagoshima University, Korimoto 1-21-40, Kagoshima 890-0065, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Tawaratsumida
authors.forename: Maiko
authors.initials: M
authors.lastname: Furuyashiki
authors.forename: Mami
authors.initials: M
authors.lastname: Katsumoto
authors.forename: Yukari
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Fukase
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Suda
authors.forename: Masahito
authors.initials: M
authors.lastname: Hashimoto
mesh_terms: D000818:Animals; D008074:Lipoproteins / Q000737:chemistry* / Q000378:metabolism*; D013058:Mass Spectrometry; D051379:Mice; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism*; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*
chemical_list: D008074:Lipoproteins; D051195:Toll-Like Receptor 2