Proteasomal Profiling for Low-Abundance Peptide Detection

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Solution Overview

Problem

Current methods for analyzing proteasome dynamics in cells face challenges such as the dynamic range of protein abundance and complexity of tissues, making it difficult to detect low-abundance or rapidly turning over proteins, and they do not provide insights into protein activity or function over time.

Innovation Solution

A method called 'Proteasomal Profiling' is developed, which involves purifying proteasomes using specific antibodies, stabilizing peptides with peptidase inhibitors and cross-linkers, and subjecting them to mass spectrometry analysis to identify peptides actively processed by barrel-like proteases, allowing for the isolation and characterization of the active degradome.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mass spectrometry analysis is performed on bulk biological samples, then global protein identification is achieved, but low-abundance and rapidly turning over proteins cannot be detected

Engineering Contradiction:
Improvedetection sensitivityVSAvoidprotein abundance
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The invention extracts and isolates the proteasome complex from bulk cellular proteins using immunoprecipitation with specific antibodies. This extraction enables focused analysis of proteasome-associated peptides, allowing detection of low-abundance proteins that would be masked in bulk sample analysis.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the complex proteome into proteasome-processed peptides and other cellular proteins. By separating and analyzing only the proteasome-associated fraction, the method achieves sensitive detection of specific protein degradation products without interference from the vast majority of cellular proteins.

Inventive Principle:
Principle #1Segmentation

2Loss of information

If conventional mass spectrometry is used to analyze tissue proteins, then abundant proteins are identified, but insights into protein activity or function over time are not provided

Engineering Contradiction:
Improveprotein activity informationVSAvoidanalysis throughput
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The invention performs preliminary action by treating cells with proteasome inhibitors before lysis, which prevents degradation of proteins during sample preparation. This preliminary inhibition preserves the proteomic state at a specific time point, enabling analysis of protein activity dynamics without loss of information.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses proteasome inhibitors as intermediaries to capture and preserve information about protein degradation activity. These inhibitors act as mediators that freeze the proteolytic process, allowing subsequent detection of degradation products that reflect protein activity at the time of treatment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If proteasomes are isolated without maintaining peptide content, then purification is achieved, but processed peptides are lost

Engineering Contradiction:
Improvepurification easeVSAvoidpeptide content
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The invention applies beforehand cushioning by using proteasome inhibitors and cross-linkers during the isolation process. These agents protect and stabilize the peptide content within proteasomes throughout purification, preventing peptide loss while maintaining ease of manufacture through standardized protocols.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 detection of low-abundance and short-lived proteins, providing insights into cellular processes and regulatory proteins, and offers a novel way to analyze proteome dynamics, enhancing the identification of key regulators in various biological conditions.

Implementation Method 1

purifying proteasomes using specific antibodies

Methodology Applied
Scientific EffectAntibody-antigen binding:

Implementation Method 2

stabilizing peptides with peptidase inhibitors

Methodology Applied
Scientific EffectEnzyme inhibition: Enzyme

Implementation Method 3

stabilizing peptides with peptidase inhibitors and cross-linkers

Methodology Applied
Scientific EffectChemical cross-linking: Chemical Bonding

Implementation Method 4

subjecting them to mass spectrometry analysis to identify peptides actively processed by barrel-like proteases

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 5

Mass spectrometry (MS) analysis has provided tremendous achievements in the ability to decode the proteasome and identify global changes of proteins

Methodology Applied
Scientific EffectMass spectrometry detection:

Data Source

PatentEP3430161B1Methods of isolating barrel-like proteases and identifying peptides processed thereby
Publication Date: 2024.05.01 YEDA RES & DEV CO LTD
  • EP3430161B1 patent drawingFigure 1
  • EP3430161B1 patent drawingFigure 2
  • EP3430161B1 patent drawingFigure 3A~3B

AI summary

A method of isolating barrel-like proteases is disclosed. The method comprising isolating barrel-like proteases from a biological sample containing the barrel-like proteases under conditions that maintain the content of the barrel-like protease- processed peptides in the barrel-like proteases upon isolation. A method of isolating barrel-like protease-processed peptides and a method of identifying barrel-like protease- processed peptides are also disclosed.