ANTIBODY-RIBOSOME-MESSENGER-RNA (ARM) COMPLEXES AS EFFICIENT SELECTION PARTICLES FOR IN-VITRO DISPLAY AND EVOLUTION OF ANTIBODY COMBINING SITES

We describe a rapid, eukaryotic, in vitro method for selection and evo lution of antibody combining sites using antibody-ribosome-mRNA (ARM) complexes as selection particles, ARMs carrying single-chain (V-H/K) b inding fragments specific for progesterone were selected using antigen -coupled magnetic beads; selection simultaneously captured the genetic information as mRNA, making it possible to generate and amplify cDNA by single-step RT-PCR on the ribosome-bound mRNA for further manipulat ion, Using mutant libraries, antigen-binding ARMs were enriched by a f actor of 10(4)-10(5)-fold in a single cycle, with further enrichment i n repeated cycles, While demonstrated here for antibodies, the method has the potential to be applied equally for selection of receptors or peptides from libraries.