Cell-Free Protein Synthesis with Chaperones

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Solution Overview

Problem

Bacterial cell-free protein synthesis systems face challenges with slower growth rates and lower protein synthetic activity due to overexpression of proteins, leading to improper folding and loss of biological activity, necessitating improved extracts with enhanced chaperone expression for proper protein folding.

Innovation Solution

Incorporating a bacterial extract with an active oxidative phosphorylation system and exogenous protein chaperones like disulfide isomerase and peptidyl-prolyl cis-trans isomerase, expressed at high concentrations, to improve the expression and folding of biologically active proteins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If proteins are overexpressed during bacterial growth to provide cell-free synthesis systems with altered properties, then the protein synthetic activity in extracts is improved, but the bacterial growth rate slows down and the protein folding quality deteriorates

Engineering Contradiction:
Improveprotein synthetic activityVSAvoidprotein folding quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-expressing chaperone proteins (DsbC and FkpA) in the bacterial host before preparing the cell-free extract. This ensures that chaperones are already present in the extract at high concentrations, enabling proper protein folding to occur during the cell-free synthesis process without requiring additional optimization steps later.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses chaperone proteins as intermediaries to mediate between the overexpressed target protein and the folding environment. Specifically, DsbC acts as an intermediary for disulfide bond formation and FkpA for proline isomerization, facilitating proper folding of the target protein during cell-free synthesis.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If chaperone proteins are added to the cell-free synthesis system to improve proper folding, then the biological activity of expressed proteins is improved, but the system complexity increases

Engineering Contradiction:
Improvebiological activityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by engineering the bacterial host to autonomously produce and accumulate chaperone proteins (DsbC and FkpA) during growth. The cell-free extract then inherently contains these chaperones, eliminating the need for external addition or complex optimization of chaperone concentrations during the cell-free synthesis process.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the concentration parameter of chaperone proteins in the cell-free extract by engineering the bacterial host to overexpress them. This results in extracts with inherently high chaperone concentrations, simplifying the system by eliminating the need for external chaperone addition and optimization.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If extracts are prepared from bacteria overexpressing chaperones to synthesize large amounts of properly folded protein, then the yield of biologically active protein is improved, but the extraction process complexity increases

Engineering Contradiction:
Improveyield of biologically active proteinVSAvoidextraction process complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The bacterial host autonomously produces and accumulates chaperone proteins during growth, and these chaperones are automatically incorporated into the cell-free extract during preparation. This self-service approach eliminates the need for complex post-extraction chaperone addition or optimization steps.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent applies preliminary action by pre-expressing chaperone proteins in the bacterial host before extract preparation. This ensures that chaperones are already present in the extract at high concentrations, enabling proper protein folding to occur during the cell-free synthesis process without requiring additional optimization steps later.

Inventive Principle:
Principle #10Preliminary action

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

The method significantly increases the production of properly folded and biologically active proteins, achieving higher yields and maintaining bacterial growth rates by synergistically enhancing protein expression and folding processes.

Implementation Method 1

The cell-free synthesis system comprises a bacterial extract having an active oxidative phosphorylation system

Methodology Applied
Scientific EffectOxidative phosphorylation:

Implementation Method 2

exogenous protein disulfide isomerase

Methodology Applied
Scientific EffectDisulfide isomerase catalysis: Enzyme

Implementation Method 3

exogenous peptidyl-prolyl cis/trans isomerase

Methodology Applied
Scientific EffectProlyl isomerase catalysis: Enzyme

Data Source

PatentEP2986731B1Expression of biologically active proteins in a bacterial cell-free synthesis system using cell extracts with elevated levels of exogenous chaperones
Publication Date: 2022.05.18 SUTRO BIOPHARMA INC
  • EP2986731B1 patent drawingFigure 1
  • EP2986731B1 patent drawingFigure 2A
  • EP2986731B1 patent drawingFigure 2B

AI summary

The present disclosure describes methods and systems for improving the expression of a properly folded, biologically active protein of interest in a cell free synthesis system. The methods and systems use a bacterial cell free extract having an active oxidative phosphorylation system, and include an exogenous protein chaperone. The exogenous protein chaperone can be expressed by the bacteria used to prepare the cell free extract. The exogenous protein chaperone can be a protein disulfide isomerase and/or a peptidyl-prolyl cis-trans isomerase. The inventors discovered that the combination of a protein disulfide isomerase and a peptidyl-prolyl cis-trans isomerase produces a synergistic increase in the amount of properly folded, biologically active protein of interest.