Biotin binders selected from a random peptide library expressed on phage

Area of Science:

• Biotechnology
• Molecular Biology
• Biochemistry

Background:

• Biotin-binding proteins like streptavidin are crucial in molecular biology and diagnostics.
• Developing novel, non-avidin binders for biotin is of significant interest for research and therapeutic applications.
• Phage display is a powerful technique for discovering ligands with specific binding properties.

Purpose of the Study:

• To identify novel biotin-binding peptides using phage display technology.
• To characterize the binding affinity and inhibitory potential of discovered peptides.
• To establish a new class of small molecule biotin binders.

Main Methods:

• Affinity selection of recombinant phages from a random peptide library.
• Sequencing of selected phage inserts to identify peptide motifs.
• Synthesis and testing of a peptide containing the identified motif for streptavidin binding inhibition.

Main Results:

• Identification of a novel biotin-binding motif: CXWXPPF(K or R)XXC.
• A synthetic peptide with this motif showed half-maximal inhibition of phage binding at micromolar concentrations.
• The synthetic peptide inhibited streptavidin binding to biotinylated BSA with an IC50 of 50 microM.
• This represents the shortest non-avidin biotin-binding peptide discovered to date.

Conclusions:

• Phage display technology is effective for discovering novel ligands for small molecules like biotin.
• The identified peptide motif represents a new class of small, non-avidin biotin binders.
• This discovery has potential applications in diagnostics, therapeutics, and biochemical research.