HL-A Antigens from Hematopoietic Cell Lines: Molecular Size and Electrophoretic Mobility

Abstract

HL-A antigens of hematopoietic cells in long-term culture were solubilized by papain digestion, and the molecular size and electrophoretic mobility of the fragments carrying individual HL-A specificities were estimated. HL-A1, HL-A2, HL-A7 and HL-A8 specificities were present on molecular fragments of 48,000 Daltons. An unidentified alloantigenic specificity was present on molecular fragments of 74,000 Daltons. Although all the HL-A active fragments migrated to the α₂ globulin region upon electrophoresis, the mobility of the molecular fragments carrying HL-A2 specificity was slightly lower than those of fragments having the other specificities. All papain fragments of HL-A2 specificity from different cell lines were identical in molecular size and electrophoretic mobility. A similar identity also appeared to be present among the papain fragments carrying the other specificities.