Knottins: disulfide-bonded therapeutic and diagnostic peptides

Knottins have emerged as an important class of molecules for the development of peptide-based drugs due to the exceptional thermal and proteolytic stability conferred by their cystine-knot core. Several naturally occurring knottins have already entered the clinic for therapeutic applications, and knottins with novel molecular recognition properties and biological activities have been engineered using rational and combinatorial methods. Recently, knottins have also shown exciting promise as non-invasive molecular imaging agents for use in diagnostic applications.