Synthesis and secretion of an albumin-like protein by cultured bovine tracheal gland serous cells.

Bovine tracheal submucosal gland serous cells were incubated with (35S) methionine. The proteins synthesized and secreted into the culture medium during pulse and chase periods were analyzed. Three major protein bands with apparent molecular weight values of 67 kD, 47 kD and 32 kD were detected by fluorography following SDS-polyacrylamide gel electrophoresis. Based on the molecular weight, immuno-reactive cross reactivity and surface molecular change characteristics, the labeled Mr 67 kD protein was identified as an albumin-like protein. Our results suggest that albumin found in airway secretions can originate, at least in part, from tracheal gland serous cells.