Adhiron: a stable and versatile peptide display scaffold for molecular recognition applications

Area of Science:

• Protein engineering and molecular recognition.
• Development of novel non-antibody scaffolds for biotechnology.

Background:

• Antibodies are widely used for molecular recognition but can be challenging to produce.
• There is a need for stable, well-expressed alternative scaffolds for binding applications.

Purpose of the Study:

• To design and characterize a novel non-antibody protein scaffold, Adhiron, for molecular recognition.
• To create and validate a high-complexity phage-display library based on the Adhiron scaffold.
• To demonstrate the utility of Adhirons in selecting specific binding reagents.

Main Methods:

• Design of Adhiron scaffold based on phytocystatin consensus sequence.
• Expression in E. coli and X-ray crystallography for structural determination.
• Construction of a large phage-display library (1.3 x 10^10 clones).
• Screening against yeast Small Ubiquitin-like Modifier (SUMO) and other targets.

Main Results:

• Adhiron exhibits high thermal stability (Tm ~101°C) and good expression in E. coli.
• X-ray structure reveals a compact, cystatin-like fold.
• Selected Adhirons show low nanomolar affinity and high specificity for yeast SUMO.
• Binders identified for over 100 targets, including FGF1, PECAM-1, and Grb2 SH2 domain.

Conclusions:

• Adhirons are highly stable and well-expressed protein scaffolds.
• Adhiron-based phage display enables selection of highly specific binding reagents.
• Adhirons represent a promising alternative to antibodies for diverse molecular recognition applications.