Hemopoietin 1 (H-1) and the mononuclear phagocyte specific growth factor CSF-1 act synergistically on developmentally early bone marrow cells to generate primitive CSF-1 receptor-bearing cells. The H-1 activity of the serum-free medium conditioned by the human urinary bladder carcinoma cell line 5637 was shown to result from the sum of the activities of two charged species (pI ~4.8, ~85%; pI ~5.3, ~15%) of similar size. No qualititative difference in the biological activity of these two species was detected. A four-step procedure, involving batch DEAE-cellulose chromatography, chromatofocusing, gel filtration, and hydrophobic chromatography has been developed for the major (pI ~4.8) species. H-1 was purified approximately 65,000-fold and recovered as 32% of the total activity of the starting material. The lowest concentration yielding maximal biological activity was ~0.25 ng/ml. The 125I-labeled purified H-1, in either native or reduced form, behaved as a homogeneous single band that coelectrophoresed with the biological activity of purified H-1 on sodium dodecyl sulfate gel electrophoresis (NaDodSO4/PAGE). The molecular mass of the purified reduced H-1, determined by NaDodSO4/PAGE was ~17 kDa. Recent studies indicate that the purified H-1 is a multilineage hemopoietic growth factor.
|Number of pages
|Proceedings of the National Academy of Sciences of the United States of America
|Published - 1985
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