TRL-C Quantification via Enzymatic Selectivity

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Solution Overview

Problem

Current methods for measuring triglyceride-rich lipoprotein cholesterol (TRL-C) are labor-intensive, costly, and do not accurately quantify IDL-C, which is clinically meaningful, as they either require ultracentrifugation or NMR instruments or rely on methods that include IDL-C in LDL-C measurements.

Innovation Solution

A method using a cholesterol esterase with a molecular weight over 50 kDa and specific surfactants like polyoxyethylene polycyclic phenyl ethers to selectively eliminate cholesterol from lipoproteins other than TRL, allowing for accurate quantification of TRL-C without separation operations, using a kit that includes cholesterol esterase and surfactants to enzymatically decompose and measure hydrogen peroxide produced.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ultracentrifugation method is used to measure TRL-C, then measurement accuracy is improved, but operation complexity and time consumption increase significantly

Engineering Contradiction:
ImproveTRL-C measurement accuracyVSAvoidoperation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical ultracentrifugation system with an enzymatic reaction system. Instead of using ultracentrifugation to separate lipoproteins by density, the invention uses cholesterol esterase with molecular weight >50 kDa to selectively hydrolyze cholesterol esters in TRL-C, followed by colorimetric detection. This substitution eliminates complex separation equipment while achieving accurate TRL-C measurement through enzyme specificity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from physical separation based on density to biochemical reaction based on enzyme substrate specificity. By selecting cholesterol esterase with molecular weight greater than 50 kDa, the method exploits the enzyme's inability to penetrate certain lipoprotein structures, creating a selective reaction that occurs only with TRL-C, thereby simplifying the measurement process while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If NMR method is used to measure TRL-C, then measurement accuracy is improved, but equipment availability and cost decrease

Engineering Contradiction:
ImproveTRL-C measurement accuracyVSAvoidequipment availability
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, specialized NMR equipment with inexpensive, disposable enzyme reagents. The cholesterol esterase-based assay uses readily available enzymes and standard colorimetric detection, eliminating the need for costly NMR instruments. The reagents can be prepared and used in routine laboratory settings, making the method widely accessible without specialized equipment.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If calculation method is used to measure TRL-C, then ease of operation is improved, but measurement precision deteriorates due to inclusion of IDL-C in LDL-C

Engineering Contradiction:
Improvemeasurement convenienceVSAvoidTRL-C quantification accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent extracts the IDL-C component from the LDL-C measurement by using cholesterol esterase with molecular weight >50 kDa. This enzyme selectively reacts with TRL-C (including IDL-C) but not with LDL-C, allowing IDL-C to be measured separately. The extracted IDL-C value can then be used to calculate accurate TRL-C levels without the contamination that occurs in standard calculation methods where IDL-C is incorrectly included in LDL-C.

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

This method enables convenient and accurate quantification of TRL-C, including IDL-C, using an automatic analyzer, providing results that correlate well with ultracentrifugation methods, thus overcoming the limitations of existing techniques.

Implementation Method 1

cholesterol esterase having a molecular weight of more than 50 kDa as measured by SDS-polyacrylamide gel electrophoresis specifically reacts with lipoproteins other than TRL

Methodology Applied
Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 2

a surfactant(s) to act; and (2) specifically quantifying the remaining TRL-C, wherein in cases where said surfactant used in said step (1) is one surfactant, said surfactant is one selected from the group consisting of polyoxyethylene polycyclic phenyl ether having an HLB value of 12 to 14

Methodology Applied
Scientific EffectSurfactant effect: Surfactant

Implementation Method 3

the step (2) comprises allowing cholesterol esterase and cholesterol oxidase to act and then quantifying produced hydrogen peroxide

Methodology Applied
Scientific EffectOxidation reaction: Oxidation

Data Source

PatentEP3467120B1Method and reagent for quantifying cholesterol in triglyceride-rich lipoprotein
Publication Date: 2023.11.08 DENKA CO LTD
  • EP3467120B1 patent drawingFigure 1

AI summary

Disclosed are a method and reagent of quantifying cholesterol in triglyceride-rich lipoprotein (TRL-C) in a test sample in a more specific manner without requiring laborious operations. The method of quantifying cholesterol in triglyceride-rich lipoprotein (TRL-C) includes the steps of: (1) selectively eliminating cholesterol in lipoproteins other than triglyceride-rich lipoprotein (TRL) by allowing a cholesterol esterase having a molecular weight of more than 50 kDa and a surfactant(s) to act; and (2) quantifying the remaining TRL-C.