title: Protein identification with Liquid Chromatography and Matrix Enhanced Secondary Ion Mass Spectrometry (LC-ME-SIMS).
abstract: Secondary Ion Mass Spectrometry (SIMS) is a well established method for sensitive surface atomic and molecular analysis. Protein analysis with conventional SIMS has been attempted numerous times; however it delivers exclusively fragment peaks assigned to α-amino acids or immonium ions. In this paper we report experiments where direct sequence information could be measured thanks to a combination of HPLC separation with matrix enhanced SIMS (ME-SIMS) on tryptic digests of intact proteins. We employ peptide mass fingerprinting (PMF) and protein identification through the detection of HPLC-separated digests of Savinase (Sav.) and bovine serum albumin (BSA), followed by MASCOT search. This is the first time that the possibility of full protein identification using LC-ME-SIMS is demonstrated in a classic proteomics workflow and that a 69kDa protein is identified with SIMS. These results demonstrate both the relevance and the potential of LC-ME-SIMS in future high resolution proteomics studies.
authors.affiliation: FOM-Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Luke
authors.initials: L
authors.lastname: MacAleese
authors.forename: Marc C
authors.initials: MC
authors.lastname: Duursma
authors.forename: Leendert A
authors.initials: LA
authors.lastname: Klerk
authors.forename: Greg
authors.initials: G
authors.lastname: Fisher
authors.forename: Ron M A
authors.initials: RM
authors.lastname: Heeren
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D010449:Peptide Mapping / Q000379:methods; D040901:Proteomics / Q000379:methods*; D020539:Sequence Analysis, Protein / Q000379:methods*; D012697:Serine Endopeptidases / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000032:analysis; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*
chemical_list: D012710:Serum Albumin, Bovine; D012697:Serine Endopeptidases; C032923:microbial serine proteinases