FIG. 4.

Endo H sensitivity of class I molecules. BJAB/EF, BJAB/K3, and BJAB/K5 cells were metabolically labeled with [³⁵S]methionine and [³⁵S]cysteine for 15 min and chased for 0, 20, or 40 min. Radioactively labeled lysates were used for immunoprecipitation with an anti-class I antibody. Immunoprecipitates were treated with endo H prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The portion of the gel displaying the heavy chain of class I molecules is shown. ∗, the endo H-resistant heavy chain of class I molecules.