Purification and characterization of a bovine colostrum-derived growth factor.
A growth factor in bovine colostrum was purified to homogeneity by a combination of acid extraction, boiling, cation exchange chromatography, isoelectric focusing, and reverse phase HPLC. The bovine colostrum growth factor (BCGF) had an isoelectric point of about 10, a native mol wt of about 30,000, was resistant to inactivation by boiling and exposure to pH 1, but was inactivated by dithiothreitol. BCGF appeared to be structurally related to human platelet-derived growth factor (PDGF) and competed with human PDGF in a radioreceptor assay. However, while human PDGF appeared to be a heterodimer of 17,000 and 14,000 mol wt subunits, BCGF appeared to be a homodimer of 20,000 mol wt subunits. Purified BCGF had a specific activity in stimulating 3T3 cell proliferation of about 3-6 U/ng and was active at about 1-2 ng/ml.
Shing
Y
Y
Department of Biological Chemistry, Children's Hospital, Boston, Massachusetts 02115.
Klagsbrun
M
M
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003126:Colostrum / Q000032:analysis*; D004261:DNA Replication / Q000187:drug effects; D005260:Female; D006133:Growth Substances / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D046911:Macromolecular Substances; D008894:Milk Proteins; D008970:Molecular Weight; D010982:Platelet-Derived Growth Factor / Q000302:isolation & purification
D006133:Growth Substances; D046911:Macromolecular Substances; D008894:Milk Proteins; D010982:Platelet-Derived Growth Factor; C041826:colostrum growth factor