A Simple Whole-Plasmid PCR Method to Construct High-Diversity Synthetic Phage Display Libraries

Area of Science:

• Biotechnology
• Molecular Biology
• Immunology

Background:

• Phage display is a powerful technique for identifying specific binding molecules using diverse libraries.
• Producing these libraries is often labor-intensive and technically demanding.
• Commercial library ownership can restrict the use of selected binders.

Purpose of the Study:

• To develop a streamlined and efficient method for generating high-diversity peptide and VHH antibody phage display libraries.
• To demonstrate the utility of these libraries in selecting specific ligands and for applications like epitope mapping and antibody discovery.

Main Methods:

• A whole-plasmid PCR and type IIS restriction enzyme assembly cloning strategy was employed.
• Peptide libraries (1x10^9 variants) for gene VIII display and VHH antibody libraries (12mer, 16mer, 21mer CDR3s) in cAbBCII10 scaffold for gene III display were generated.
• Library diversity and bias were assessed, and functionality was confirmed via biopanning.

Main Results:

• The method reproducibly generated libraries with approximately 1x10^9 variants from minimal transformations with low bias (82-86% single-copy sequences).
• Peptide libraries were successfully used for epitope mapping of a monoclonal antibody.
• VHH libraries were utilized to select an antibody targeting recombinant human collagen type 1.

Conclusions:

• The described cloning strategy offers a simple, efficient, and reproducible approach to creating high-quality, low-bias phage display libraries.
• These versatile libraries facilitate the selection of specific binders for diverse biological applications, including antibody development and epitope mapping.