Tamavidin 2-REV: an engineered tamavidin with reversible biotin-binding capability

Area of Science:

• Biochemistry
• Protein Engineering
• Biotechnology

Background:

• Reversible biotin-binding proteins are crucial for purifying biotinylated biomolecules.
• Existing engineered avidin/streptavidin variants have limitations.
• Tamavidin 2 is a fungal biotin-binding protein with potential for modification.

Purpose of the Study:

• To engineer a tamavidin 2 mutein with reversible biotin-binding properties.
• To evaluate the efficacy of the engineered protein in affinity purification.
• To characterize the binding affinity and properties of the novel mutein.

Main Methods:

• Site-directed mutagenesis of tamavidin 2 to create tamavidin 2-REV (S36A).
• Affinity chromatography using tamavidin 2-REV immobilized on agarose resin.
• Purification of biotinylated bovine serum albumin from E. coli extracts.
• Determination of the dissociation constant (Kd) for tamavidin 2-REV and biotin.

Main Results:

• Tamavidin 2-REV demonstrated efficient binding to biotin-agarose and elution with free biotin at neutral pH.
• Single-step purification of biotinylated bovine serum albumin was achieved.
• The dissociation constant (Kd) for tamavidin 2-REV to biotin was determined to be 2.8-4.4×10(-7)M.
• Tamavidin 2-REV maintained high-level expression, protease resistance, and a neutral isoelectric point.

Conclusions:

• Tamavidin 2-REV exhibits reversible biotin-binding capability.
• This engineered protein is a powerful tool for the efficient purification of biotinylated biomolecules.
• Tamavidin 2-REV offers a promising alternative to existing biotin-binding proteins for biotechnological applications.