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Comparison of bovine and porcine β‐lactoglobulin: a mass spectrometric analysis
Author(s) -
Invernizzi Gaetano,
Šamalikova Maria,
Brocca Stefania,
Lotti Marina,
Molinari Henriette,
Grandori Rita
Publication year - 2006
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1019
Subject(s) - chemistry , dimer , electrospray ionization , dissociation (chemistry) , mass spectrometry , monomer , denaturation (fissile materials) , beta lactoglobulin , folding (dsp implementation) , solvent , chromatography , whey protein , nuclear chemistry , organic chemistry , polymer , electrical engineering , engineering
Abstract Nano‐electrospray‐ionization mass spectrometry (nano‐ESI‐MS) is applied to comparison of bovine and porcine β‐lactoglobulin (BLG and PLG). The conformational and oligomeric properties of the two proteins under different solvent and experimental conditions are analyzed. The pH‐dependence of dimerization is described for the pH range 2–11. The results indicate maximal dimer accumulation at pH 6 for BLG and pH 4 for PLG, as well as a lower stability of the PLG dimer at pH 4 compared to BLG at pH 6. Conformational stability appears to be higher for BLG at acidic pH, but higher for PLG at basic pH. The higher stability of BLG at low pH is revealed by means of either chemical or thermal denaturation. Equilibrium folding intermediates of both proteins are detected. Finally, conditions are found that promote dissociation of the BLG dimer at pH 6 into folded monomers. Copyright © 2006 John Wiley & Sons, Ltd.