Synthesis and Properties of an EGF-like Domain (residues 361-406) in the Extreme N-terminal Region of the Mouse EGF Precursor

AbstractVarious proteins contain EGF-like domains that are not ligands for the EGF receptor. In the present study a cognate polypeptide for residues 361-406 of the mouse EGF precursor was synthesized by the solid-phase method. The product was renatured under oxidative conditions since it probably has an EGF-like array of three cystine disulfide bonds in its native state. HPLC analysis of the renaturation reaction revealed formation of a peak material with no apparent free-SH groups. Accordingly, the HPLC retention time of this product was readily increased by treatment(reduction of disulfides) with dithiothreitol. The renatured 46-mer (PEGF-1) did not displace 125 I-EGF bound to rat liver membranes and 125I-PEGF-l did not exhibit specific binding to membrane preparations from the mouse liver, mammary gland, or kidney, with or without Ca2+ in the binding medium. Although PEGF-1 contains a putative Ca2+ binding motif, specific binding of this cation by the polypeptide could not be demonstrated by electromob...