Peptides for targeting βB2-crystallin fibrils.

Area of Science:

• Ophthalmology
• Biochemistry
• Protein Science

Background:

• Cataracts, a leading cause of vision loss, result from insoluble protein aggregates in the eye lens, primarily crystallins.
• Current cataract treatment, surgery, is inaccessible in many regions, necessitating alternative therapeutic strategies.
• Targeting specific protein structures involved in cataract formation is crucial for developing novel pharmacotherapies.

Purpose of the Study:

• To identify and characterize peptides that specifically bind to βB2-crystallin fibrils, a model for cataract-associated aggregates.
• To validate the potential of these peptides as therapeutic agents for non-surgical cataract treatment.

Main Methods:

• Recombinant human βB2-crystallin was fibrillated in vitro and characterized using Thioflavin-T assay, transmission electron microscopy (TEM), and X-ray fiber diffraction (XRFD).
• Phage display techniques were employed to identify peptides with high affinity for βB2-crystallin fibrils.
• Enzyme-linked immunosorbent assay (ELISA) and competitive inhibition assays were used to quantify peptide binding affinity.

Main Results:

• Amyloid-like structure of βB2-crystallin fibrils was confirmed through multiple biophysical analyses.
• Phage display successfully identified peptides that bind to the βB2-crystallin fibrils.
• A specific cyclic peptide (CKQFKDTTC) demonstrated the highest binding affinity, validated by competitive inhibition assays.

Conclusions:

• High-affinity peptides capable of targeting βB2-crystallin fibrils were identified.
• These findings represent a significant step towards developing targeted pharmacotherapies for cataracts.
• The identified peptides offer potential for novel, non-surgical treatment strategies for vision impairment.