Multiplex Transgenic Protein Analysis via LC-MS/MS

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Solution Overview

Problem

Current methods for analyzing transgenic plants are inefficient in identifying and quantifying multiple transgenic gene products in a high-throughput manner, often requiring purified proteins, empirical testing, and are prone to contamination and misinterpretation due to the presence of Agrobacterium or reporter genes.

Innovation Solution

A high-throughput method using mass spectrometry that involves extracting proteins from plant tissue with ammonium bicarbonate, digesting them into peptides, and injecting the crude sample into an LC-MS/MS device to detect and quantify specific proteins of interest without the need for purified samples or method-specific reagents, allowing for simultaneous analysis of multiple proteins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DNA-based techniques (PCR) are used to analyze transgenic plants, then genetic transformation can be detected, but the results are misleading due to presence of Agrobacterium contamination and do not confirm actual protein expression

Engineering Contradiction:
Improveaccuracy of transgenic detectionVSAvoidinability to confirm protein expression
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent replaces DNA-based detection methods with mass spectrometry-based protein detection. Instead of using PCR to detect transgenic DNA sequences, the invention directly detects and quantifies the actual protein products of transgene expression through mass spectral analysis, thereby confirming true protein expression rather than just genetic presence

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

Solution Approach 2:

The patent changes the detection parameter from genetic DNA sequences to actual protein molecules. By using mass spectrometry to detect protein mass-to-charge ratios and fragmentation patterns, the method directly measures the physical presence and quantity of transgenic protein products, providing reliable confirmation of actual expression

Inventive Principle:
Principle #35Parameter changes

2Reliability

If immunochemistry methods are used to identify transgene products, then protein expression can be detected, but highly-purified protein samples are required and antibodies must be produced and tested

Engineering Contradiction:
Improvespecificity of transgene product detectionVSAvoidcomplexity of sample preparation and reagent development
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs mass spectrometry as a universal detection method that does not require transgene-specific reagents. The same mass spectrometry platform can detect any transgenic protein by analyzing its characteristic mass-to-charge ratio and fragmentation pattern, eliminating the need for separate antibody production and validation for each transgene

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent extracts and removes the requirement for complex reagent systems (antibodies) and highly-purified samples. By using direct mass spectral analysis of crude plant extracts, the method eliminates the need for antibody production, purification steps, and reagent-specific optimization that characterize immunochemical approaches

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If reporter genes are used to identify transformants, then transformation can be visually detected, but reporter gene expression does not confirm transgene expression and genes may be lost in successive generations

Engineering Contradiction:
Improvesimplicity of transformant identificationVSAvoidaccuracy of transgene expression confirmation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces indirect reporter gene detection with direct mass spectrometry-based protein detection. Instead of relying on fluorescent or colorimetric reporters that may not correlate with transgene expression, the invention directly detects the actual transgenic protein products through their characteristic mass spectral signatures

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

Solution Approach 2:

The patent uses mass spectral data as a direct copy or fingerprint of the transgenic protein itself. By analyzing the unique mass-to-charge ratios and fragmentation patterns of peptide sequences, the method creates a molecular copy of the protein identity that directly confirms transgene expression without requiring separate reporter systems

Inventive Principle:
Principle #26Copying

4Measurement precision

If gel electrophoresis separation is used before mass spectrometry analysis, then protein mixtures can be separated, but the process is time-consuming and impedes high-throughput applications

Engineering Contradiction:
Improveresolution of protein separationVSAvoidthroughput of analysis
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts and removes the gel electrophoresis separation step from the mass spectrometry workflow. By using direct liquid chromatography-mass spectrometry (LC-MS) analysis of crude protein extracts, the invention eliminates the time-consuming gel separation, electrophoresis, and band excision steps while maintaining the ability to resolve and identify individual proteins through their characteristic mass spectral fingerprints

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements a continuous liquid chromatography-mass spectrometry workflow that continuously analyzes protein peptides as they elute from the chromatography column. This continuous analysis approach eliminates the discrete, batch-processing nature of gel electrophoresis and enables high-throughput analysis by continuously generating mass spectral data without interruption for gel manipulation

Inventive Principle:
Principle #20Continuity of useful 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

Enables rapid and accurate detection and quantification of transgenic proteins directly from complex samples, reducing the need for purified proteins and empirical testing, and facilitating bioconfinement and maintenance of transgenic traits across generations.

Implementation Method 1

injecting the digested crude plant matrix into an LC-MS/MS device; obtaining simultaneous mass spectral data for the peptides

Methodology Applied
Scientific EffectMass spectrometry:

Data Source

PatentEP2437869B2Multiplex analysis of stacked transgenic protein
Publication Date: 2023.05.03 DOW AGROSCIENCES LLC
  • EP2437869B2 patent drawingFigure 1
  • EP2437869B2 patent drawingFigure 2
  • EP2437869B2 patent drawingFigure 3

AI summary

The invention relates to methods for multiplex analysis of complex protein samples from plants using mass spectroscopy. In some embodiments, the disclosure concerns methods for maintaining a transgenic plant variety, for example by analyzing generations of a transgenic plant variety for presence and concentration of multiplexed transgenic proteins.