title: Establishment of LC-MS methods for the analysis of palmitoylated surfactant proteins.
abstract: The surfactant proteins (SPs), SP-B and SP-C, are important components of pulmonary surfactant involved in the reduction of alveolar surface tension. Quantification of SP-B and SP-C in surfactant drugs is informative for their quality control and the evaluation of their biological activity. Western blot analysis enabled the quantification of SP-B, but not SP-C, in surfactant drugs. Here, we report a new procedure involving chemical treatments and LC-MS to analyze SP-C peptides. The procedure enabled qualitative analysis of SP-C from different species with discrimination of the palmitoylation status and the artificial modifications that occur during handling and/or storage. In addition, the method can be used to estimate the total amount of SP-C in pulmonary surfactant drugs. The strategy described here might serve as a prototype to establish analytical methods for peptides that are extremely hydrophobic and behave like lipids. The new method provides an easy measurement of SP-C from various biological samples, which will help the characterization of various experimental animal models and the quality control of surfactant drugs, as well as diagnostics of human samples.
authors.affiliation: Department of Lipid Signaling, Research Institute, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Harayama
authors.affiliation: Department of Lipid Signaling, Research Institute, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan CREST, Japan Science and Technology Agency, Kawaguchi-shi, Saitama 332-0012, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Shindou
authors.affiliation: Department of Lipidomics, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kita
authors.affiliation: Department of Lipid Signaling, Research Institute, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan Advanced Medical Research Department, Research Division, Mitsubishi Tanabe Pharma Corporation, Yokohama-shi, Kanagawa 227-0033, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Otsubo
authors.affiliation: Division of Neonantology, Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka-shi, Iwate 020-8505, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Chida
authors.affiliation: Division of Pulmonary Biology, Medical Center, Cincinnati Children's Hospital, Cincinnati, OH 45229-3026.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Weaver
authors.affiliation: Department of Lipid Signaling, Research Institute, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan Department of Lipidomics, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D054878:Lipoylation; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D010446:Peptide Fragments / Q000032:analysis; D037701:Pulmonary Surfactant-Associated Protein B / Q000032:analysis* / Q000737:chemistry*; D037721:Pulmonary Surfactant-Associated Protein C / Q000032:analysis* / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D010446:Peptide Fragments; D037701:Pulmonary Surfactant-Associated Protein B; D037721:Pulmonary Surfactant-Associated Protein C; D013501:Surface-Active Agents
keywords: drug therapy; liquid chromatography; lung; mass spectrometry; palmitoylation; proteomics; pulmonary surfactant; surfactant drug