title: Purification and characterization of cell growth factor in bovine colostrum.
abstract: Bovine colostrum has growth factor activity for stimulating DNA synthesis in calf kidney epithelial cells (CKT-1), Madincanine kidney epithelial cells (MDCK) and rat L6 myoblasts (L6), of which the DNA stimulation level and the activity change with the time elapsed after the birth of a calf varied with their respective cells. The growth factor activity of colostrum for CKT-1 was stable regardless of the collection time of colostrum, and it was purified about 3,650-fold in an overall yield of 1.2% from colostrum obtained 30 min after the birth of a calf. The purified growth factor had a molecular weight (MW) of 5,000 and an isoelectric point of pH 9.7, and the amino acid composition was: Asx5, Thr2, Ser4, Glx14, Pro2, Gly4, Ala4, Val2, Ile, Leu2, Tyr, Phe, Lys, His and Arg. The stimulated DNA synthesis in CKT-1 and L6 by the addition of purified growth factor at a final concentration of 16ng/ml was as the same extent as calf serum at a final concentration of 1.52 mg/ml, and the relative activity for CKT-1 was even greater than that for L6.
authors.affiliation: Laboratorie of Physiological Chemistry, College of Agriculture and Veterinary Medicine, Nihon University, Kanagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kishikawa
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: S
authors.initials: S
authors.lastname: Kubo
mesh_terms: D016475:3T3 Cells; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000831:Animals, Newborn; D001681:Biological Assay; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003126:Colostrum / Q000737:chemistry*; D004247:DNA / Q000096:biosynthesis; D004285:Dogs; D005260:Female; D006133:Growth Substances / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000737:chemistry* / Q000494:pharmacology; D007668:Kidney; D051379:Mice; D008895:Milk, Human / Q000737:chemistry; D051381:Rats; D013997:Time Factors
chemical_list: D000596:Amino Acids; D006133:Growth Substances; D007334:Insulin-Like Growth Factor I; D004247:DNA