| Popis: |
Dulak and Temin(1) first reported that the BRL-3A cell line established from normal rat liver secreted a family of polypeptides, which they termed MSA, that had multiplication-stimulating activity for chick embryo fibroblasts. MSA was purified by Moses and colleagues from conditioned media using Dowex chromatography, Sephadex G-75 gel filtration in 1 M acetic acid, and preparative gel electrophoresis, and shown to appear in multiple forms of Mr 16.3K, 8.7K, and 7.1K.(2) Marquardt et al. (3) purified MSA by a different purification scheme (i.e., Bio-Gel P-10 in 1 M acetic acid and high-performance liquid chromatography), and determined the amino acid sequence of a Mr 7484-dalton form. Mr 7484 MSA appears to correspond to our Mr 7.1K species. It is identical to human IGF-II at 62 of 67 amino acid loci, establishing that BRL-MSA represents the rat homologue of IGF-II.(3) |
