FIG. 4.

U21 does not discriminate against the products of different class I loci. (A) Class I complexes from control and U21-expressing cells were precipitated with either W6/32 or a polyclonal anti-U21 Ab and separated by SDS-PAGE. (B) IEF gel of W6/32 and α-U21 immunoprecipitations shown in panel A. Lanes 3, 4, 7, and 8 are from the same samples as those in lanes 1 to 4 from the SDS-PAGE gel in panel A. Heavy chains of class I (HC), β₂m, and sialylated class I heavy chain molecules are indicated.