Immunoprecipitation of integrins from NQ22 cells.
Approximately 2.5 × 107 cells were radiolabeled with 125I and extracted in lysis buffer. (A) Aliquots of the cell lysate were immunoprecipitated using the following antibodies: lane 1, anti-α4 (R1-2); lane 2, anti-β7 (M298); lane 3, anti-α4β7 (DATK-32); lane 4, anti-α6β1 (GoH3). (B) Sequential immunoprecipitations. NQ22 cell lysates were first depleted with 3 rounds of immunoprecipitation with anti-β7 (lane 1), followed by 3 rounds with anti-α4 (lane 2), and finally with the polyclonal anti-β1 antibody (lane 3). Samples were then analyzed by SDS-PAGE on a 7% gel under nonreducing conditions. The migration of standard molecular weight markers is shown in the center. The migration of integrin α and β chains is also indicated.
