Bovine brain-derived growth factor. Purification and characterization of its interaction with responsive cells.

摘要: A large-scale purification procedure for brain-derived growth factors, without chromatography in 0.1% trifluoracetic acid, has been developed. Two related factors have purified to homogeneity from bovine brain using this involving ammonium sulfate fractionation, followed by on CM-Sephadex C-50, sulfated Sephadex G-50, and heparin-Sepharose 4B. Brain-derived factor (BDGF-A, molecular weight approximately 16,000) B (BDGF-B, 17,000) were eluted 4B at 1.2 1.6 M NaCl, respectively. Both BDGF-A BDGF-B a pI value of 5.7, the same specific mitogenic activity, react with mouse anti-BDGF-A antiserum. broad spectrum activity (vascular aorta endothelial cells, chondrocytes, osteoblasts, epithelial glial fibroblasts, smooth muscle cells), half-maximum effect 10-20 pM. The binding BDGF cells Swiss 3T3 characterized. Binding 125I-BDGF-A these reached equilibrium less than 15 min. Scatchard plot analysis showed single class high-affinity receptor Kd values 20 +/- 5 13 3 pM numbers/cell 7,000 1,000 20,000 3,000, competed manner as unlabeled BDGF-A, suggesting that bind receptor. Basic pituitary fibroblast appeared be weak inhibitor, whereas platelet-derived epidermal had no binding. Protamine, histone, polylysine, polyarginine are potent inhibitors responsive cells. half-time (t1/2) internalization degradation cell surface-bound 125I-BDGF is h.