title: Nonaqueous capillary electrophoresis in coated capillaries: an interesting alternative for proteomic applications.
abstract: This work brings together some contributions for the use of nonaqueous media for proteomic analysis, for both capillary electrophoresis (CE) separation and the preparation of tryptic digests. First, a ternary nonaqueous buffer consisting of 60/30/10 v/v methanol/acetonitrile/acetic acid with 12.5 mmol/L ammonium acetate was optimized for CE separation of the tryptic digest of lysozyme. Lysozyme was chosen as a model system for the protein digestion, which has also been prepared in an organic-rich medium with methanol/50 mmol/L NH(4)HCO(3), pH 8.0 (60/40 v/v). The separation results were compared to in silico (PeptideCutter program) digestion conditions, and high-efficiency peak separation (18 peaks) was obtained in 20 min with an electric field of 350 V/cm. In addition, we have evaluated the stability of a coated capillary with poly-N,N-dimethylacrylamide (60/30 cm total/effective length and 75 microm ID) for over 100 runs of tryptic digest with the nonaqueous background electrolyte solvent system. The migration times for ten selected peptide peaks presented 3-7% relative standard deviation.
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, Brazil.
authors.forename: Nilson A
authors.initials: NA
authors.lastname: Assunção
authors.forename: Leandro A Grange
authors.initials: LA
authors.lastname: Deziderio
authors.forename: Luis G
authors.initials: LG
authors.lastname: Paulino
authors.forename: Karina O
authors.initials: KO
authors.lastname: Lupetti
authors.forename: Emanuel
authors.initials: E
authors.lastname: Carrilho
mesh_terms: D002021:Buffers; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D040901:Proteomics; D015203:Reproducibility of Results; D014357:Trypsin / Q000737:chemistry
chemical_list: D002021:Buffers; D014357:Trypsin