Expression and one-step purification of intracellular human prolactin in insect cells

Human prolactin was expressed in insect culture cells by recombinant baculo viruses carrying prolactin gene cDNA placed under the transcriptional contr ol of polyhedrin gene promoter of Autographa californica nuclear polyhedros is virus. Preliminary:results of recombinant human prolactin expression as extracellular as well as intracellular product of baculovirus expression sy stem were presented at the FEES Meeting in Nice, France, in 1999 (Abstracts , p. 288). In the present work prolactin was expressed as a hexahistidine-t agged fusion protein and recombinant protein was purified by metal affinity resin, Yields varied between approximately 20 and 35 mg/liter of medium. T his recombinant prolactin was biologically active in Nb2 lymphoma cell prol iferation assay and after simple purification could substitute for pituitar y-derived prolactin. (C) 2001 Academic Press.