Truncated DME Polypeptide for Improved Solubility and Yield

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Solution Overview

Problem

Current methods for producing DEMETER (DME) protein in E. coli face challenges due to its large size and poor solubility, limiting expression yield and stability, which hampers the efficient excision of 5-methylcytosine from DNA.

Innovation Solution

Engineering DME by removing the interdomain region 1 (IDR1) and replacing it with a short linker peptide, resulting in a truncated form (DMEΔN677ΔIDR1::lnk) that is more soluble and stable, allowing for higher expression levels and improved purification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If full-length DME protein is produced in E. coli, then demethylase activity is maintained, but expression yield and solubility are poor

Engineering Contradiction:
Improvedemethylase activityVSAvoidexpression yield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts and removes the problematic interdomain region 1 (IDR1) from the full-length DME protein. This deletion resolves the solubility and expression issues while preserving the essential demethylase activity located in other domains of the protein.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the structural parameters of the DME protein by deleting specific amino acid sequences (IDR1 region). This structural modification transforms the protein from insoluble/full-length to soluble/truncated form, improving expression yield while maintaining functional activity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If full-length DME protein is produced in E. coli, then demethylase activity is maintained, but protein stability is poor

Engineering Contradiction:
Improvedemethylase activityVSAvoidprotein stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The unstable IDR1 interdomain region is extracted and removed from the protein structure. This elimination of the unstable region directly improves overall protein stability while the remaining stable domains maintain demethylase function.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If full-length DME protein is produced in E. coli, then complete functional domains are present, but purification is difficult

Engineering Contradiction:
Improvefunctional completenessVSAvoidpurification ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By removing the IDR1 region that complicates purification, the truncated protein structure becomes easier to manufacture and purify. The essential functional domains remain intact, ensuring complete demethylase activity.

Inventive Principle:
Principle #2Taking out (Extraction)

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 truncated DMEΔN677ΔIDR1::lnk form maintains demethylase activity, significantly increasing expression yield and solubility, and is successfully purified with enhanced stability, facilitating efficient 5-methylcytosine excision from DNA.

Implementation Method 1

the polypeptide excises methylated cytosines in DNA when contacted to DNA comprising methylated cytosines

Methodology Applied
Scientific EffectDemethylase activity: Enzyme

Data Source

PatentEP2421881B1Engineered demeter 5-methylcytosine DNA glycosylase with improved yield, stability and solubility
Publication Date: 2016.04.13 RGT UNIV OF CALIFORNIA
  • EP2421881B1 patent drawingFigure 1
  • EP2421881B1 patent drawingFigure 2
  • EP2421881B1 patent drawingFigure 3

AI summary

Improved active DEMETER polypeptides with internal deletions are provided.