Two forms of murine epidermal growth factor: rapid separation by using reverse-phase HPLC.
Epidermal growth factor (EGF) has been isolated from acid extracts of C57BL6/J mouse submaxillary glands by using hydrophobic chromatography. High yields of EGF in large amounts (10 mg) can be isolated reliably from the acid extract of the glands in less than 4 hr. The reverse-phase HPLC techniques used to purify the EGF initially yielded what appeared to be a single homogeneous EGF molecule. However, ion pairing reagents (e.g., heptafluorobutyric acid) altered the chromatographic properties, revealing two distinct species: EGF-alpha and EGF-beta. The apparent molecular weights, isoelectric points, and antigenic properties of EGF-alpha and EGF-beta were identical, and both forms stimulated a mitogenic response in 3T3 cells. Analysis of different preparations of purified EGF (commercial and experimental) indicated the presence of EGF-alpha and EGF-beta in constant proportion. Previous EGF binding studies must have used mixtures of 125I-labeled EGF-alpha and 125I-labeled EGF-beta. The two molecules appear to compete for an identical receptor on the cell surface.
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004815:Epidermal Growth Factor / Q000302:isolation & purification*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D012997:Solvents; D013363:Submandibular Gland / Q000032:analysis
D012997:Solvents; D004815:Epidermal Growth Factor