title: Murine epidermal growth factor: structure and function.
abstract: Murine epidermal growth factor (EGF), a 53 amino acid protein, has been modified by enzymic digestion, site-specific chemical reactions, and recombinant DNA technology. After trypsin digestion the EGF derivatives EGF1-48 (called EGF-T) and EGF1-45 (called EGF-T2) were separated from the residual EGF and the C-terminal pentapeptide by reversed-phase high-performance liquid chromatography. EGF-T competes for binding to EGF receptors with the same efficiency as EGF. The EGF-T2 derivative had no detectable receptor binding activity even at 100 nM. The in vitro mitogenic potencies of EGF and EGF-T for Balb/c 3T3 cells were indistinguishable. Treatment of EGF-T with carboxypeptidase Y yielded two derivatives, EGF-T-(des-Arg48) and EGF-T-des(Leu47-Arg48). There was only a 3-7-fold diminution in the binding efficiency and mitogenic potency for EGF-T-(des-Arg48). However, there was more than a 100-fold decrease in the binding efficiency and mitogenic activity of EGF-T-des (Leu47-Arg48). These results indicated that Leu47 is intimately involved in the formation of the ligand-receptor complex. Studies with a number of proteases indicated that the C-terminus of EGF was susceptible to enzymic digestion; however, the N-terminus appears to be folded into a conformation which prevents access to proteolytic digestion. Consequently, the N-terminus was modified by preparing an analogue with recombinant DNA technology. Oligonucleotides corresponding to EGF(3-48). Met3 Lys21 residues were ligated in frame to a beta-galactosidase expression vector. The beta-Gal-EGF fusion protein was cleaved with cyanogen bromide and EGF(4-48).Lys21 purified.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Melbourne Tumour Biology Branch, Ludwig Institute for Cancer Research, Victoria, Australia.
authors.forename: A W
authors.initials: AW
authors.lastname: Burgess
authors.forename: C J
authors.initials: CJ
authors.lastname: Lloyd
authors.forename: S
authors.initials: S
authors.lastname: Smith
authors.forename: E
authors.initials: E
authors.lastname: Stanley
authors.forename: F
authors.initials: F
authors.lastname: Walker
authors.forename: L
authors.initials: L
authors.lastname: Fabri
authors.forename: R J
authors.initials: RJ
authors.lastname: Simpson
authors.forename: E C
authors.initials: EC
authors.lastname: Nice
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D004815:Epidermal Growth Factor / Q000032:analysis / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D013329:Structure-Activity Relationship
chemical_list: D004815:Epidermal Growth Factor