Characterization of recombinant glycosylated human interleukin 2 produced by a recombinant plasmid transformed CHO cell line.

A recombinant plasmid containing expression units for human pre-interleukin 2 (pre-IL-2) and the selectable marker mouse DHFR, was constructed and used to transform DHFR- CHO cells to the DHFR+ phenotype. Selected colonies were isolated and tested for IL-2 production. Twelve highly IL-2-producing clones were amplified in stepwise increasing concentrations of methotrexate.

Expression vector promoting the synthesis and export of the human growth-hormone-releasing factor in Escherichia coli.

We have studied the synthesis, processing and export of human growth-hormone-releasing factor (hGRF) in Escherichia coli transformed with a plasmid constructed for the expression of hGRF as a hybrid protein. A DNA fragment containing the entire sequence of phosphate-binding protein gene (phoS) is fused to a modified hGRF-coding sequence (phoS-mhGRF). The hybrid protein, PhoS-mhGRF, was recovered in the supernatant fluid after spheroplasting treatment indicating correct export to the periplasmic space.

Abundant excretion of human growth hormone by recombinant-plasmid-transformed monkey kidney cells.

A recombinant plasmid was constructed permitting the efficient synthesis of human growth hormone (hGH) in monkey cells. The plasmid contains the cDNA sequence of the hGH precursor and controlled by the SV40 early promoter, an intron, and the poly(A)-addition site of the mouse alpha-globin gene. To permit selection of transformed cells, a selectable marker (xanthine-guanine phosphoribosyl transferase; XGPRT) was also introduced into this plasmid.

Messenger RNA extracted from Schistosoma mansoni larval forms codes for parasite antigens when translated in vitro.

Intact messenger RNA was extracted from three stages of development of the parasite Schistosoma mansoni, cercariae, 3 h (mechanically prepared) schistosomula and adults. Some of the in vitro translation products are precipitable with immune rat and human serum showing that these sera recognize protein determinants. Whereas the patterns of the total translation products show major proteins expressed at all three developmental stages, immunoprecipitation delineates patterns unique to each stage.

Improved method for cloning DNA complementary to minor mRNAs: preparation of a hybridization probe from purified mRNAs encoding intermediate filament proteins.

A procedure for the rapid fractionation of mRNA has been used to enrich mRNAs encoding a set of intermediate filament proteins in trophoblastoma cells. The procedure involves sucrose-gradient fractionation followed by high-resolution preparative gel electrophoresis. Part of the enriched mRNA preparation has been used to prepare a hybridization probe to screen a trophoblastoma cDNA library in Escherichia coli.