Immunoprecipitation analysis of α_IIbβ₃ complexes from CHO cells transiently cotransfected with α_IIb and either normal or mutant forms of β₃. CHO cells were transiently transfected with α_IIb and either normal β₃ or β₃(616-690del), β₃Δ616, β₃Δ638, β₃Δ657, β₃Δ675, or β₃Δ693 cDNA constructs. Cells were incubated with [35S]-methionine-cysteine for 3 hours. Cell lysates were immunoprecipitated with anti-β₃ or anti-α_IIb and processed as described in “Materials and methods.”