Isolation and characterization of coactivator-binding peptoids from a combinatorial library

Area of Science:

• Molecular Biology
• Synthetic Chemistry

Background:

• Developing pharmacologic agents to control gene expression is crucial for biological research and therapeutics.
• Cell-permeable mimics of transcription factors, combining DNA-binding and activation domains, are a key focus.
• Previous work identified a peptoid, KBPo2, that binds a fragment of CREB-binding protein (CBP).

Purpose of the Study:

• To detail the screening experiments for identifying peptoid mimics of transcription factor activation domains.
• To further characterize KBPo2 and other identified peptoids.
• To evaluate the potential of KBPo2 as a cell-permeable activation domain mimic.

Main Methods:

• Screening for peptoids that bind to CREB-binding protein (CBP).
• Characterization of identified peptoids for binding affinity, specificity, and cell permeability.
• Assessing the ability of peptoids to act as activation domain mimics in human cells when linked to a DNA-binding domain.

Main Results:

• Three peptoids were identified as putative CBP ligands.
• Only KBPo2 exhibited the required binding affinity, specificity, and cell permeability.
• KBPo2 functions as a potent activation domain mimic in human cells.
• KBPo2 binds to a distinct region on CBP compared to the native CREB activation peptide.

Conclusions:

• KBPo2 is a potent and cell-permeable mimic of transcription factor activation domains.
• This peptoid represents a valuable tool for biological research and potential therapeutic applications.
• The distinct binding site of KBPo2 on CBP offers opportunities for targeted modulation of coactivator function.