FIG. 3.

MHC class I HC fragments in K3-BJAB cells lack the cytoplasmic tail. MHC class I complexes were immunoprecipitated from K3-BJAB lysates after a 30-min pulse and 2 h of chase in the absence (lane 1) or presence (lane 2) of 50 μM ZL₃VS. The immunoprecipitates were boiled in SDS, and the released material was then immunoprecipitated with HC70 (lanes 3 and 4) or p8 (lanes 5 and 6). HC70 recognizes the lumenal fragment of unfolded MHC class I HC; p8 recognizes the cytoplasmic tail of MHC class I HC.