title: Characterization of proteins from Spirulina platensis microalga using capillary electrophoresis-ion trap-mass spectrometry and capillary electrophoresis-time of flight-mass spectrometry.
abstract: In this work, a new capillary electrophoresis-mass spectrometry (CE-MS) procedure is developed to analyze proteins in Spirulina platensis microalgae. It is demonstrated that a fine optimization of several separation parameters is essential in order to achieve suitable CE-MS analysis of these proteins in natural extracts from microalgae. Namely, optimization of the composition of the separation buffer, electrospray conditions, and washing routine between runs are required in order to obtain reliable and reproducible CE-MS analyses of the main proteins found in this microalga (namely, allophycocyanin-alpha chain, allophycocyanin-beta, c-phycocyanin-alpha, and c-phycocyanin-beta). The relative molecular mass of these biopolymers is determined using two different MS instruments coupled to CE, i.e., CE-ion trap-MS and CE-time of flight-MS (CE-TOF-MS). A comparison between the results obtained with both instruments is carried out. The high resolution of the TOF-MS enables the distinction of small modifications in proteins and, thus, a more accurate mass determination. Interestingly, molecular mass values obtained by both CE-MS procedures agree very well while these experimental values are only in partial agreement with those theoretically expected (i.e., genetically derived masses). Some protein modifications due to amino acids exchange induced by nucleotide codon mutations are proposed to explain this difference.
authors.affiliation: Department of Food Analysis, Institute of Industrial Fermentations (CSIC), Madrid, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Simó
authors.forename: Miguel
authors.initials: M
authors.lastname: Herrero
authors.forename: Christian
authors.initials: C
authors.lastname: Neusüss
authors.forename: Matthias
authors.initials: M
authors.lastname: Pelzing
authors.forename: Ernst
authors.initials: E
authors.lastname: Kenndler
authors.forename: Coral
authors.initials: C
authors.lastname: Barbas
authors.forename: Elena
authors.initials: E
authors.lastname: Ibáñez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cifuentes
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis* / Q000302:isolation & purification; D000458:Cyanobacteria / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D045342:Light-Harvesting Protein Complexes / Q000032:analysis* / Q000302:isolation & purification; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes