Characterization of a glycoprotein isolated from a continuous tumor-cell line of human lung carcinoma

A glycoprotein with a molecular weight of 62 000 has been isolated from a tumor-cell line, A549, and purified to homogeneity by gel chromatography. The glycoprotein contained sialic acid, galactose, mannose, N-acetylglucosamine and a relatively high amount of glutamic acid and proline. The data indicated that the overall composition of this glycoprotein was different from that of the glycoprotein of Mr 62 000 isolated from lung lavage of patients with alveolar proteinosis. The glycoprotein did not react with the antiserum raised against glycoprotein of Mr 62 000 isolated from lung lavage of patients with alveolar proteinosis.