Engineering of Peptide-Inserted Base Editors with Enhanced Accuracy and Security.

Area of Science:

• Biochemistry
• Molecular Biology
• Genetic Engineering

Background:

• Base editors enable precise DNA base conversions without double-strand breaks, crucial for biotechnology and medicine.
• Existing base editors face challenges with bystander mutations and off-target effects, raising safety concerns.

Purpose of the Study:

• To develop a novel method for enhancing base editor precision and safety.
• To investigate the impact of peptide insertions on base editor performance.

Main Methods:

• Insertion of specific peptide fragments into the deaminase substrate binding pocket of base editors.
• Testing A3A-based cytosine base editors and TadA-8e-based adenine base editors with peptide modifications.
• Evaluating editing activity, precision, bystander mutations, and off-target effects in HEK293T cells.

Main Results:

• Peptide composition and insertion site significantly influenced base editor performance.
• A TadA-8e variant with a DPLVLRRRQ peptide insertion demonstrated high motif preference (Y4A5N6) for precise adenine base editing.
• Minimized bystander and off-target effects were observed at both DNA and RNA levels.
• The peptide insertion strategy is compatible with traditional amino acid modifications.

Conclusions:

• Peptide insertion into base editors is a viable strategy to enhance editing precision and safety.
• Systematic procedures for peptide engineering can be applied to improve other base editors.
• This approach holds promise for safer gene editing applications in biotechnology and clinical settings.