| abstract |
BSF-1 was derived from malignant cells and purified by use of various techniques, including adsorption, ion exchange chromatography and reverse phase high performance liquid chromatography. By these techniques. the BSF-1 was purified to homogeneity. The high purification of the BSF-1 has made possible the sequencing of the amino acid residues at the N-terminal portion of its protein molecules. From the amino acid sequencing information, a radiolabeled oligonucleotide probe corresponding to a portion of the amino acid sequence of the BSF-1 molecule was synthesized and then used to probe a cDNA library prepared from polyadenylated mRNA extracted from cell lines known to produce BSF-1. Through this procedure, a cDNA clone containing the BSF-1 gene was isolated, sequence and mature BSF-1 expressed. The isolated cDNA clone was then radiolabeled and used as a large probe for screening cDNA libraries of other species of animals for homologous BSF-1 clones. |