title: From SELDI-TOF MS to protein identification by on-chip elution.
abstract: SELDI-TOF MS has been demonstrated as a powerful tool for biomarker discovery. However, a major disadvantage of SELDI-TOF MS is the lack of direct identification of the discriminatory peaks discovered. We describe a novel experimental identification strategy where peptides/proteins captured to a weak cation exchange ProteinArray surface (CM10) are eluted, and thereafter identified by utilizing a sensitive LC-MS/MS (i.e. LTQ Orbitrap). A mixture of four known proteins was used to test the novel experimental approach described, and all four proteins were successfully identified. Additionally, a biomarker candidate previously discovered in plasma of Atlantic cod (Gadus morhua) by SELDI-TOF MS was identified. Thus, this study indicated that a combination of on-chip elution and a highly sensitive LC-MS/MS system can be an alternative approach to identify biomarker candidates discovered by use of SELDI-TOF MS.
authors.affiliation: International Research Institute of Stavanger (IRIS), PB 8046, N-4068 Stavanger, Norway. mam@iris.no
authors.forename: Mari
authors.initials: M
authors.lastname: Mæland Nilsen
authors.forename: Kai-Erik
authors.initials: KE
authors.lastname: Uleberg
authors.forename: Emiel A M
authors.initials: EA
authors.lastname: Janssen
authors.forename: Jan P A
authors.initials: JP
authors.lastname: Baak
authors.forename: Odd Ketil
authors.initials: OK
authors.lastname: Andersen
authors.forename: Anne
authors.initials: A
authors.lastname: Hjelle
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000032:analysis / Q000378:metabolism*; D029941:Fish Proteins / Q000032:analysis / Q000097:blood*; D048389:Gadus morhua / Q000097:blood*; D040081:Protein Array Analysis / Q000379:methods; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods
chemical_list: D001798:Blood Proteins; D029941:Fish Proteins