title: Application of proteomics to the characterization of beta-lactoglobulin genetic variants by capillary electrophoresis-mass spectrometry and nano-liquid chromatography-mass spectrometry-mass spectrometry.
abstract: This report presents an analytical strategy for the identification of beta-lactoglobulin (beta-Lg) variants or isoforms in bovine milk by using capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) and nano-liquid chromatography-electrospray-mass spectrometry-mass spectrometry (nano-LC-ESI-MS-MS). beta-Lg isoforms were separated and collected by CE, and their molecular masses were determined by CE-ESI-MS. Protein isoforms collected by CE were digested with trypsin and analyzed by nano-LC-ESI-MS-MS. Isoforms analyzed by CE-ESI-MS presented multiply charged ions that after deconvolution resulted in molecular masses of 18,364 +/- 1.0 Da and 18,279 +/- 2.0 Da. Fragmentation of parent ions in MS-MS experiments of specific tryptic peptides were carried out to identify beta-Lg variants in milk samples. The milk samples analyzed were indeed phenotypes AA, BB, or AB.
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo, AC, Hermosillo, Sonora, Mexico. vallejo@cascabel.ciad.mx
authors.forename: Belinda
authors.initials: B
authors.lastname: Vallejo-Cordoba
authors.forename: Aarón F
authors.initials: AF
authors.lastname: González-Córdova
authors.forename: Héctor A
authors.initials: HA
authors.lastname: Olguin-Arredondo
mesh_terms: D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D007782:Lactoglobulins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D007782:Lactoglobulins