title: Analysis of recombinant and modified proteins by capillary zone electrophoresis coupled with electrospray ionization tandem mass spectrometry.
abstract: A method for rapid characterization of recombinant and modified proteins with known sequences is described. The analytical system consists of a capillary zone electrophoresis (CZE) instrument coupled to an electrospray ionization ion trap tandem mass spectrometer via a sheath-flow interface. Following the procedure consists of proteolytic fragmentation, CZE peptide separation, tandem mass spectrometry (MS-MS) analysis of separated peptides, sequence database search and monitoring of the specific peptides, C 125 S mutated interleukin 2 (S-125-IL2) and bovine beta-casein were characterized as a model of recombinant protein and naturally modified protein, respectively. A tryptic peptide mixture derived from the synthetic salmon calcitonin (s-CT) was also analyzed to test the performance of the system. Although a conventional sheath-flow interface with much higher flow-rate compared to the microspray interface and nanospray interface was used, the proteins were identified at the low picomole level.
authors.affiliation: Shanghai Institute of Biochemistry, Chinese Academy of Sciences, China.
authors.forename: T
authors.initials: T
authors.lastname: Liu
authors.forename: X X
authors.initials: XX
authors.lastname: Shao
authors.forename: R
authors.initials: R
authors.lastname: Zeng
authors.forename: Q C
authors.initials: QC
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002364:Caseins / Q000032:analysis*; D002417:Cattle; D019075:Electrophoresis, Capillary / Q000379:methods*; D007376:Interleukin-2 / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D017354:Point Mutation; D011994:Recombinant Proteins / Q000032:analysis*
chemical_list: D002364:Caseins; D007376:Interleukin-2; D011994:Recombinant Proteins