Fig. 3.

Time course of non-O-glycosylated mucin polypeptide synthesis. HBECs were pulse labeled for 15 min with [³⁵S]methionine and chased for 0, 10, 20, 30, 60, and 120 min. Non-O-glycosylated molecular intermediates were immunoprecipitated from cell lysates with LUM-5B13. Immunoprecipitates were subjected to agarose gel electrophoresis and after electrophoresis the gel was treated with 10 mM DTT to reduce the mucins, which were then transferred to nitrocellulose by vacuum blotting prior to detection of incorporated radioactivity by phosphoimaging. NPM, native polypeptide monomer; NPD, native polypeptide dimer.