DNA-binding peptides searched from the solid-phase combinatorial library with the use of the magnetic beads attaching the target duplex DNA

We have exhibited successful and rapid screening of DNA-binding peptide lig ands from solid-phase library beads with the use of the target DNA-conjugat ed magnetic beads. The target duplex DNA (3) has a polyether linker between two complementary sequences (T(4)A(3)G-ether linker-CT(3)A(4)) and is stab le in the duplex form during the selection procedure. Finally, 71 pentapept ide sequences were identified from the solid-phase pentapeptide library. Fr om an analysis of the peptide sequences identified in this study, it has be en revealed that peptide ligands contain hydrophobic amino acids as the maj or component. The synthetic peptides with identified sequences and a combin ation of the major components have exhibited moderate to high binding affin ity to the duplex DNA in competition experiments with ethidium-DNA complexe s. (C) 2000 Elsevier Science Ltd. ALI rights reserved.