Azide-Resistant Catalase Subunit for Clinical Measurement Error Reduction

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Solution Overview

Problem

Measurement errors in clinical tests due to inhibition of catalase by azide contamination, which affects the accurate decomposition of hydrogen peroxide from non-target components, leading to inaccurate quantification of substances like neutral fat, LDL cholesterol, HDL cholesterol, and creatinine.

Innovation Solution

Employing catalases with a subunit molecular mass of 75 kDa or higher derived from microorganisms, such as Podospora anserina or Aspergillus fumigatus, which are less sensitive to azide inhibition, to decompose hydrogen peroxide in measurement systems, thereby reducing measurement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If catalase derived from bovine is used to decompose hydrogen peroxide, then the catalase effectively eliminates hydrogen peroxide from non-target components, but the catalase is strongly inhibited by azide contamination leading to measurement errors

Engineering Contradiction:

Improvecatalase activityVSAvoidazide inhibition

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the source parameter of catalase from bovine to microorganism, and specifies a molecular mass parameter of 75 kDa or higher for the catalase subunit. This parameter change makes the catalase less sensitive to azide inhibition while maintaining its hydrogen peroxide decomposition capability, thereby resolving the contradiction between catalase activity and azide inhibition.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If azide-containing reagents are used in the measurement system, then antiseptic protection is provided, but azide vaporization contaminates the measurement system and inhibits catalase

Engineering Contradiction:

Improveantiseptic protectionVSAvoidazide vaporization contamination

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of azide contamination into a beneficial situation by using azide-resistant catalase from microorganisms. This catalase maintains high activity even in the presence of azide, allowing the measurement system to tolerate azide-containing reagents without suffering from catalase inhibition, thus converting the previously harmful azide presence into an acceptable condition.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If conventional catalase is used in automatic analyzers, then hydrogen peroxide decomposition is achieved, but cross-contamination through reagent-collecting probes causes measurement errors

Engineering Contradiction:

Improvemeasurement throughputVSAvoidquantification accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the catalase source parameter from bovine to microorganism-derived catalase with subunit molecular mass of 75 kDa or higher. This parameter change provides azide resistance that prevents measurement errors from cross-contamination in automatic analyzers, while maintaining the productivity of the measurement system.

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 allows for more accurate quantification of components like neutral fat, LDL cholesterol, and creatinine by minimizing the impact of azide contamination on catalase activity, resulting in improved measurement precision.

Implementation Method 1

a method wherein hydrogen peroxide generated from substances other than the component to be measured is decomposed to water and oxygen by the action of catalase

Methodology Applied

Scientific EffectCatalase enzyme action: Enzyme

Implementation Method 2

a method using peroxidase wherein a phenol-based or aniline-based hydrogen donor compound is allowed to react with hydrogen peroxide to convert the hydrogen peroxide to a colorless quinone

Methodology Applied

Scientific EffectPeroxidase enzyme action: Enzyme

Data Source

PatentUS10415077B2Method of reducing measurement error caused by catalase inhibition by azide

Publication Date: 2019.09.17 DENKA SEIKEN CO LTD

AI summary

Disclosed is a method for reducing measurement errors due to inhibition of catalase by azide in a method for quantification of a component to be measured, in which hydrogen peroxide derived from a component other than the component to be measured is decomposed by a catalase. The method for reducing measurement errors due to inhibition of catalase by azide employs a catalase which has a subunit having a molecular mass of 75 kDa or higher and is derived from a microorganism, when hydrogen peroxide derived from a component other than the component to be measured is decomposed by the catalase followed by quantification of hydrogen peroxide derived from the component to be measured to quantify the component to be measured.