Common acute lymphoblastic leukemia antigen: partial characterization by in vivo labeling and isolation of its messenger RNA.

Common acute lymphoblastic leukemia (ALL) antigen (CALLA)-like proteins were detected by in vivo labeling experiments carried out with human lymphoblastoid cell line KM3 and also in cell-free translation, directed by CALLA-specific mRNA prepared from immunoadsorbed KM3 polysomes. The CALLA-like structure found in both systems shows an Mr of 95kDa. Additional CALLA-like proteins could be identified in the in vivo experiments with calculated Mrs of 40kDa in the cells and 85 and 38kDa in the culture medium. In the cell-free translation system, an additional product of Mr 80kDa could be detected.