Biotinylation of protein complexes may lead to aggregation as well as to loss of subunits as revealed by Blue Native PAGE.
Blue Native polyacrylamide gel electrophoresis (BN-PAGE) is a high-resolution method for studying native protein complexes. Here, the migration behaviour of the B cell antigen receptor (BCR) in BN-PAGE with and without prior biotinylation of the cell surface, from which the complexes were purified, are compared. Non-biotinylated complexes appear as a single band, whereas biotinylated complexes display several bands, indicating that biotinylation leads to aggregation of complexes as well as to loss of subunits. Thus, BN-PAGE has limitations in studying multiprotein complexes. These results are used to gain insight into the stoichiometry of the complex.
Schamel
W W
WW
Department of Molecular Immunology, Biologie III, University of Freiburg and Max-Planck-Institut für Immunbiologie, Stübeweg 51, 79108, Freiburg, Germany. Wschamel@cbm.uam.es
D001710:Biotin / Q000737:chemistry*; D019921:Biotinylation; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D007075:Immunoglobulin M / Q000737:chemistry*; D011947:Receptors, Antigen, B-Cell / Q000737:chemistry*
D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell; D001710:Biotin