title: Laser desorption ionization mass spectrometry of protein tryptic digests on nanostructured silicon plates.
abstract: We report on the simple application of a new nanostructured silicon (NanoSi) substrate as laser desorption/ionization (LDI)-promoting surface for high-throughput identification of protein tryptic digests by a rapid MS profiling and subsequent MS/MS analysis. The NanoSi substrate is easily prepared by chemical etching of crystalline silicon in NH(4)F/HNO(3)/AgNO(3) aqueous solution. To assess the LDI performances in terms of sensitivity, repeatability and robustness, the detection of small synthetic peptides (380-1700Da) was investigated. Moreover, peptide sequencing was tackled. Various tryptic synthetic peptide mixtures were first characterized in MS and MS/MS experiments carried out on a single deposit. Having illustrated the capability to achieve peptide detection and sequencing on these ionizing surfaces in the same run, protein tryptic digests from Cytochrome C, β-Casein, BSA and Fibrinogen were then analyzed in the femtomolar range (from 50 fmol for Cytochrome C down to 2 fmol for Fibrinogen). Comparison of the NanoSi MS and MS/MS data with those obtained with sample conditioned in organic matrix demonstrated a great behavior for low mass responses. We demonstrated the capability of LDI on NanoSi to be a complementary method to MALDI peptide mass fingerprinting ensuring determination of peptide molecular weights and sequences for more efficient protein database searches.
authors.affiliation: Institut des Biomolécules Max Mousseron, UMR 5247, Universités Montpellier 1 et 2, CNRS, Bâtiment Chimie (17), Université Montpellier 2, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Dupré
authors.forename: Yannick
authors.initials: Y
authors.lastname: Coffinier
authors.forename: Rabah
authors.initials: R
authors.lastname: Boukherroub
authors.forename: Sonia
authors.initials: S
authors.lastname: Cantel
authors.forename: Jean
authors.initials: J
authors.lastname: Martinez
authors.forename: Christine
authors.initials: C
authors.lastname: Enjalbal
mesh_terms: D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D059748:Proteolysis; D040901:Proteomics / Q000379:methods*; D012825:Silicon / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D010455:Peptides; D011506:Proteins; D012825:Silicon