Novel ubiquitin-derived high affinity binding proteins with tumor targeting properties.
Targeting effector molecules to tumor cells is a promising mode of action for cancer therapy and diagnostics. Binding proteins with high affinity and specificity for a tumor target that carry effector molecules such as toxins, cytokines, or radiolabels to their intended site of action are required for these applications. In order to yield high tumor accumulation while maintaining low levels in healthy tissues and blood, the half-life of such conjugates needs to be in an optimal range. Scaffold-based binding molecules are small proteins with high affinity and short systemic circulation. Due to their low molecular complexity, they are well suited for combination with effector molecules as well as half-life extension technologies yielding therapeutics with half-lives adapted to the specific therapy. We have identified ubiquitin as an ideal scaffold protein due to its outstanding biophysical and biochemical properties. Based on a dimeric ubiquitin library, high affinity and specific binding molecules, so-called Affilin® molecules, have been selected against the extradomain B of fibronectin, a target almost exclusively expressed in tumor tissues. Extradomain B-binding molecules feature high thermal and serum stability as well as strong in vitro target binding and in vivo tumor accumulation. Application of several half-life extension technologies results in molecules of largely unaffected affinity but significantly prolonged in vivo half-life and tumor retention. Our results demonstrate the utility of ubiquitin as a scaffold for the generation of high affinity binders in a modular fashion, which can be combined with effector molecules and half-life extension technologies.
From Scil Proteins GmbH, Heinrich-Damerow-Strasse 1, 06120 Halle (Saale), Germany.
Susan
S
Lorey
Erik
E
Fiedler
Anja
A
Kunert
Jörg
J
Nerkamp
Christian
C
Lange
Markus
M
Fiedler
Eva
E
Bosse-Doenecke
Maren
M
Meysing
Manja
M
Gloser
Chris
C
Rundfeldt
Una
U
Rauchhaus
Ilka
I
Hänssgen
Thomas
T
Göttler
Arnd
A
Steuernagel
Ulrike
U
Fiedler
Ulrich
U
Haupts
D000818:Animals; D002460:Cell Line; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D009369:Neoplasms / Q000378:metabolism*; D019151:Peptide Library; D011485:Protein Binding; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D025801:Ubiquitin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000493:pharmacokinetics
D005353:Fibronectins; D019151:Peptide Library; D025801:Ubiquitin
Affilin; Biodistribution; Half-life Extension; Phage Display; Protein Engineering; Scaffold Proteins; Tumor Marker; Ubiquitin