High-level production of human α- and β-globins in insect cells

High-level production of hunan α - and β -globins in cultured Spodoptera frugiperda (Sf-9) cells infected with recombinant baculoviruses is described. The expressed globins are produced to 70–140 mg protein/liter of cell culture or 5–10% of the total cellular protein. Two recombinant baculoviruses for α -globin, H α and H βα , differ in their construction in that the 5′-untranslated region of the β -globin gene is inserted 5′ to the α -globin mRNA coding region in H βα . This insertion results in a 40% increase in yield of α -globin over that of H α . Consistent with previous observations of the processing of recombinant proteins in Sf-9 cells, both α - and β -globins expressed in Sf-9 cells are correctly processed to remove the initiating methionine from the amino termini of the globins. Sequencing of the expressed globins in Sf-9 cells confirms their identity with globins purified from human normal adult hemoglobin.