Method of obtaining small conformationally rigid conopeptides

Abstract

A method for separating, identifying and purifying small, conotoxin-like rigidly conformed peptides ('conopeptides') containing multiple Cys residues comprises forming a conoeffector library, each member of which has a nucleic acid encoding a potential conopeptide sequence. The conoeffectors are expressed such that they are exposed on the surface of a bacteriophage. These bacteriophage are screened for binding to a target protein molecule, and receptors in particular, to separate and bind phage having affinity for the target protein. Reiterative screening, if required, is used to enrich and yield a phage carrying the bound conopeptide of the desired specificity and affinity. The enriched phage are then subjected to DNA sequencing to determine the conopeptide sequence including the position of the Cys residues. The chemical structure information gathered, coupled with the binding specificities to the target protein, permits the genetic or synthetic preparation of a large variety of small rigidly conformed disulfide rich peptides as pharmaceutical, pesticidal or other bioactive candidates.