BINDING OF THE LXCXE INSULIN MOTIF TO A HEXAPEPTIDE DERIVED FROM RETINOBLASTOMA PROTEIN

Peptides corresponding to retinoblastoma protein (RB) fragment 649-654 (LFYKKV) were rested for their ability to recognize the LXCXE sequenc e motif in human papilloma virus type 16E7 protein (HPV-16E7) encompas sing E7 residues 21-26 (DLYCYE) and an identical motif in human insuli n comprising insulin B-chain residues 16-21 (YLVCGE), respectively. In teraction between these complementary peptide sequences was observed b y several approaches, including direct and competitive ELISA as well a s affinity chromatography. Moreover, we demonstrated that immobilized RB(649-654) displays specific recognition properties towards full-leng th insulin. Hence, this study provides a first experimental support fo r the previously anticipated complex formation between insulin and RE. (C) 1995 Academic Press, Inc.