Purification and partial sequence analysis of insulin-like growth factor-1 from bovine colostrum.
Growth-promoting activity in bovine colostrum has been detected as the capacity to stimulate protein synthesis in L6 myoblasts. By using this assay as a measure of bioactivity, a growth factor has been purified to near homogeneity from centrifuged colostrum by a series of steps including acid extraction, chromatography on sulphopropyl-Sephadex, followed by adsorption to, and elution from, C18 columns using acetonitrile and propan-1-ol gradients. The purified growth factor has a low solubility at neutral and alkaline pH and has an Mr of 7800 by gel-permeation chromatography. Sequence analysis of the first 30 amino acids from the N-terminus indicated complete identity in this region with human insulin-like growth factor-1. Accordingly we conclude that the purified growth factor is bovine insulin-like growth factor-1.
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003126:Colostrum / Q000032:analysis*; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000302:isolation & purification; D008970:Molecular Weight; D011247:Pregnancy
D007334:Insulin-Like Growth Factor I