Aspergillus oryzae Glucose Dehydrogenase for Oxygen-Independent Sensors

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Solution Overview

Problem

Current blood glucose sensors face challenges with enzymes like glucose oxidase due to interference from dissolved oxygen, while alternatives such as NAD(P)-dependent and pyrrolo-quinoline quinone-dependent glucose dehydrogenases have stability and specificity issues, necessitating a more stable and specific enzyme for accurate glucose monitoring.

Innovation Solution

The method involves isolating and producing glucose dehydrogenase derived from Aspergillus oryzae using gene recombination, specifically utilizing the gene encoding the enzyme to achieve stable and efficient production in Escherichia coli, thereby overcoming previous enzyme limitations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If glucose oxidase is used for blood glucose sensor, then high specificity for glucose and thermal stability are achieved, but dissolved oxygen interferes with the measured value

Engineering Contradiction:
Improveglucose measurement accuracyVSAvoiddissolved oxygen interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and eliminates the harmful dependency on dissolved oxygen by using a dehydrogenase-based enzymatic reaction that does not consume oxygen, thereby removing the source of measurement interference while preserving glucose detection capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an artificial electron mediator (such as ferrocene derivatives or viologens) as an intermediary substance that facilitates electron transfer from the dehydrogenase reaction to the electrode, replacing the need for oxygen as the electron acceptor and thereby eliminating oxygen interference

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If NAD(P)-dependent glucose dehydrogenase is used, then dissolved oxygen interference is avoided, but enzyme stability is poor and coenzyme addition is required

Engineering Contradiction:
Improvedissolved oxygen interferenceVSAvoidenzyme stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the biochemical parameters of the enzymatic system by selecting dehydrogenases with different coenzyme specificities (NAD+-dependent or NADP+-dependent) and optimizing reaction conditions such as pH, temperature, and ionic strength to enhance enzyme stability while maintaining activity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite enzymatic system by combining dehydrogenase with stable artificial mediators and immobilization matrices, forming a stable biosensor assembly that maintains enzyme activity without requiring continuous coenzyme supplementation

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If pyrrolo-quinoline quinone-dependent glucose dehydrogenase is used, then dissolved oxygen interference is avoided, but substrate specificity is inferior and reacts with other sugars

Engineering Contradiction:
Improvedissolved oxygen interferenceVSAvoidglucose measurement accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent applies local quality control by selecting dehydrogenases with specific active site structures that provide high glucose specificity, and by optimizing the local chemical environment through pH control and use of specific buffer systems that enhance substrate selectivity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes reaction parameters such as pH, temperature, and ionic strength to optimize the specificity of the dehydrogenase for glucose over other sugars, thereby improving measurement accuracy while maintaining the oxygen-independent reaction pathway

Inventive Principle:
Principle #35Parameter changes

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

This approach enables the production of a glucose dehydrogenase with improved thermal stability and specificity, reducing interference from oxygen and other sugars, thus enhancing the accuracy of blood glucose monitoring.

Implementation Method 1

The method involves isolating and producing glucose dehydrogenase derived from Aspergillus oryzae using gene recombination

Methodology Applied
Scientific EffectGene recombination:

Implementation Method 2

An enzyme taking glucose as a substrate is utilized for a sensor used for the self-monitoring of blood glucose

Methodology Applied
Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 3

NAD(P)-dependent glucose dehydrogenase (EC. 1.1.1.47) or pyrrolo-quinoline quinone-dependent glucose dehydrogenase (EC. 1.1.5.2; former EC. 1.1.99.17) is used as the enzyme for the blood glucose sensor

Methodology Applied
Scientific EffectDehydrogenase reaction:

Data Source

PatentUS7655130B2Glucose dehydrogenase from <i>Aspergillus oryzae </i>
Publication Date: 2010.02.02 TOYOBO CO LTD

AI summary

The present invention effectively produces glucose dehydrogenase derived from Aspergillus oryzae, and provides more practical glucose dehydrogenase. The invention makes it possible to efficiently produce glucose dehydrogenase and to obtain glucose dehydrogenase in more practical manner by using a glucose dehydrogenase gene isolated from Aspergillus oryzae.