A novel screening system for claudin binder using baculoviral display

Area of Science:

• Cell Biology
• Membrane Proteins
• Pharmaceutical Research

Background:

• The claudin (CL) protein family, comprising over 20 members, is a significant target in pharmaceutical therapy.
• Identifying ligands for CL proteins is challenging due to difficulties in preparing intact CL.

Purpose of the Study:

• To develop a novel screening method for CL binders using the budded baculovirus (BV) display system.
• To identify novel CL binders and modulators for potential therapeutic applications.

Main Methods:

• Utilized a CL4-displaying BV system to screen for binders.
• Employed a C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) as a known CL4 binder.
• Constructed and screened a C-CPE phage library for CL4 binders.
• Assessed the interaction of CL-displaying BV with C-CPE and mutated variants.

Main Results:

• CL4-displaying BV specifically interacted with CL4 binders, including C-CPE, but not with mutated C-CPE or other CL variants.
• The CL-displaying BV system effectively enriched CL4-binding phage from a mixed library, increasing C-CPE-phage from 16.7% to 92%.
• Screening of a mutated C-CPE phage library identified novel CL4 binders that modulated the tight-junction barrier.

Conclusions:

• The CL-displaying BV system is a viable and promising method for selecting and identifying novel CL binders.
• This approach facilitates the discovery of CL binders with potential to modulate the tight-junction barrier for therapeutic purposes.