Preliminary approaches for the development of a high-performance liquid chromatography/electrospray ionization tandem mass spectrometry method for the detection and label-free semi-quantitation of the main storage proteins of Lupinus albus in foods.
Since recent literature has indicated that white lupin (Lupinus albus) may be a useful source of hypocholesterolemic proteins to be used in functional food formulation, our final goal is the development of a fast and automated high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method for the detection and the label-free semi-quantitation of the main lupin globulins in lupin foods and food ingredients. We present here some preliminary results in this direction. As a first step a total protein extract (TPE-WF) from lupin flakes was pre-fractionated by anion-exchange chromatography and each fraction was digested with trypsin and analyzed by HPLC/ESI-MS/MS. Subsequently, the tryptic digest of TPE-WF was directly analyzed by HPLC/ESI-MS/MS without any pre-fractionation. Eventually, in order to test the applicability of the method to real samples, a lupin beverage and two lupin protein isolates were analyzed. Both Mascot and Spectrum Mill MS Proteomics Workbench software were used to identify the protein composition in these samples and Spectrum Mill was used also to test the possibility of developing a label-free semi-quantitation method based on peptide hits. Encouraging results were obtained especially in the detection of the hypocholesterolemic component beta-conglutin.
Department of Agri-Food Molecular Sciences, Laboratory of Food Chemistry and Mass Spectrometry, University of Milan, Via Celoria 2, 20133 Milan, Italy.
Daniela
D
Locati
Sheila
S
Morandi
Marco
M
Zanotti
Anna
A
Arnoldi
D000595:Amino Acid Sequence; D001628:Beverages / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D019295:Computational Biology; D004220:Disulfides / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D007202:Indicators and Reagents; D031297:Lupinus / Q000737:chemistry*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000032:analysis*; D012015:Reference Standards; D012984:Software; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000737:chemistry
D004220:Disulfides; D007202:Indicators and Reagents; D010940:Plant Proteins; D014357:Trypsin