CA2 Destabilizing Domain for Tunable Protein Expression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gene and cell therapy technologies lack the ability to titrate the timing and levels of target protein induction, making it difficult to safely and effectively deploy therapies with narrow therapeutic windows or those requiring transient expression.
Innovation Solution
The use of destabilizing domains (DDs) derived from human carbonic anhydrase 2 (CA2), which are small protein domains that render a fused protein unstable without a specific ligand but stabilize it in its presence, allowing for tunable and temporal control of protein expression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If destabilizing domains are used to control protein stability, then protein expression can be tuned temporally and dosally, but the system complexity increases due to requiring ligand binding mechanisms
Solution Approach 1:
The patent extracts the destabilizing function from complex regulatory systems and isolates it into a small, modular domain (CA2-derived DD) that can be attached to any target protein. This extracted domain works with simple small molecule ligands, reducing overall system complexity while maintaining tunable control capabilities.
Solution Approach 2:
The patent utilizes parameter changes in the CA2 protein structure through site-directed mutagenesis to create variants with different ligand binding affinities and stability characteristics. By changing amino acid residues (e.g., H122Y, E106D mutations), the system achieves tunable protein stability without increasing structural complexity.
2Reliability
If protein stability is increased for therapeutic efficacy, then treatment effectiveness improves, but the ability to control timing and duration of expression decreases
Solution Approach 1:
The patent creates a dynamic system where protein stability is not fixed but can be switched between stable and unstable states through ligand binding. The CA2-DD fusion protein dynamically responds to small molecule ligands, allowing temporal control of therapeutic protein expression while maintaining high stability when needed for efficacy.
Solution Approach 2:
The system implements feedback control where ligand binding to the CA2 domain provides stabilization feedback that maintains therapeutic protein levels. The feedback mechanism allows precise control of expression duration and timing while ensuring sufficient protein stability for therapeutic effect.
3Ease of operation
If small molecule ligands are used to stabilize proteins, then dosing flexibility is achieved, but the risk of off-target effects increases
Solution Approach 1:
The patent modifies the local quality of the CA2 domain through specific mutations (H122Y, E106D, W208S) that enhance ligand binding selectivity and affinity. These localized structural changes create a highly specific binding pocket that reduces off-target effects while maintaining dosing flexibility through small molecule variation.
Solution Approach 2:
The CA2 destabilizing domain serves as an intermediary between the small molecule ligand and the therapeutic protein. This intermediary layer provides specificity and control, allowing dosing flexibility while minimizing direct interaction between ligands and off-target proteins, thereby reducing harmful side effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables safe and effective protein therapeutics by providing controlled and dose-dependent stability of the payload protein, enhancing the precision and efficacy of gene and cell therapies.
Implementation Method 1
DDs render the attached protein of interest unstable in the absence of a DD-binding ligand and the protein of interest is rapidly degraded by the ubiquitin-proteasome system of the cell
Implementation Method 2
when a specific small molecule DD-binding ligand binds to the DD, the attached protein of interest is stabilized, and protein function is achieved
Data Source
AI summary
The present disclosure provides regulatable biocircuit systems. Such systems provide modular and tunable protein expression systems in support of the discovery and development of therapeutic modalities. In particular, the present application is directed to fusion proteins comprising a fragment of human human carbonic anhydrase 2 and a chimeric antigen receptor (CAR). The activity of the destabilizing domain can be regulated by externally administered agents.