ABSTRACT
Construction of molecular chimeras from different sources has been routine in molecular biology since gene splicing began in the middle of 1970s. For a detailed discussion of the genetics and biochemistry of molecular cloning systems, refer to the comprehensive survey of vectors edited by Rodriguez and Denhardt (1). In 1985, recombinant DNA techniques were used to fashion a new type of chimera that underlies today’s phage display technology (2). To create one of these chimeras, a foreign coding sequence is spliced in-frame into a phage coat protein gene, so that the ‘‘guest’’ peptide encoded by that sequence is fused to a coat protein and thereby displayed on
the exposed surface of the virion. A phage display library is an ensemble of up to about 10 billion such phage clones, each harboring a different foreign coding sequence, and therefore displaying a different guest peptide on the virion surface. The foreign coding sequence can derive from a natural source, or it can be deliberately designed and synthesized chemically. For instance, phage libraries displaying billions of random peptides can be readily constructed by splicing degenerate synthetic oligonucleotides into the coat protein gene.
