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Two‐dimensional gel electrophoresis/matrix‐assisted laser desorption/ionisation mass spectrometry of a milk powder
Author(s) -
Galvani Marina,
Hamdan Mahmoud,
Righetti Pier Giorgio
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/1097-0231(20001030)14:20<1889::aid-rcm109>3.0.co;2-p
Subject(s) - chemistry , chromatography , reflectron , mass spectrometry , coomassie brilliant blue , matrix assisted laser desorption/ionization , surface enhanced laser desorption/ionization , desorption , adduct , protein mass spectrometry , matrix (chemical analysis) , sample preparation in mass spectrometry , analytical chemistry (journal) , time of flight mass spectrometry , ionization , tandem mass spectrometry , electrospray ionization , organic chemistry , staining , pathology , adsorption , medicine , ion
Proteins in a commercial milk powder have been separated by two‐dimensional gel electrophoresis and analysed by matrix‐assisted laser desorption ionisation mass spectrometry. The mass spectrometric analyses were conducted in two steps: analysis of the intact proteins following their passive extraction into a suitable solvent mixture and analysis in reflectron mode of in situ digests of a number of gel spots. The combination of the two methods allowed a reliable identification of a number of proteins, including nine caseins as well as certain protein modifications including single/multiple phosphorylation, lactose‐protein conjugates and Coomassie Brilliant Blue adducts. Analyses of the intact proteins prior to their in situ digestion contributed to a more efficient and reliable consultation of protein databases. Copyright © 2000 John Wiley & Sons, Ltd.