Avacta has developed Affimer reagents and therapeutics – a class of non-antibody binding proteins that have been engineered to succeed in a wide range of applications where antibodies and aptamers have limitations. Affimer scaffolds are small (~100 amino acids, 12 kDa, 3 nm in diameter), stable (70°C <Tm < over 100°C), monomeric proteins that do not contain disulphide bonds.

Affimer molecules can be used to detect difficult targets, can easily be formatted for a wide range of applications and can be easily and cost effectively manufactured.

Two Affimer scaffolds, based on similar protein conformations, have been developed. The first, which has been artificially engineered from a plant protein, is designed for use in reagents and diagnostics, the second is a fully human version, based on the naturally occurring protein cystatin, ideal for therapeutic applications.