Bacterial Surface Protein Interaction Detection via Tat Pathway

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Solution Overview

Problem

Current methods for analyzing protein-protein interactions are limited by the need for protein purification, loss of protein functionality upon immobilization, and inefficiencies in detecting binding events, which hinder high-throughput analysis and identification of interacting proteins and potential drug compounds.

Innovation Solution

A method utilizing bacterial host cells expressing fusion proteins with a Tat signal sequence and a marker protein, allowing for the detection of protein-protein interactions by monitoring growth under selective pressure, such as antibiotic exposure, to identify interacting proteins and assess the impact of test compounds on these interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If proteins are purified and immobilized on arrays for analysis, then protein-protein interactions can be detected, but the proteins lose their ability to interact with other proteins and the process becomes complex and time-consuming

Engineering Contradiction:
Improvedetection of binding eventsVSAvoidprotein purification and immobilization
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system uses the bacterial host cell's own protein transport and expression machinery to automatically present the bait protein in its native, functional state on the cell surface, eliminating the need for manual purification and immobilization steps that would otherwise be required

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical/chemical process of protein purification and immobilization on solid supports with a biological system where living bacterial cells naturally present the protein on their surface through the Tat pathway, maintaining protein functionality while simplifying the workflow

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

2Measurement precision

If proteins are purified to create arrays, then specific binding events can be monitored, but the process requires knowing the identification of applied proteins and isolating them for determination

Engineering Contradiction:
Improvedetection of binding eventsVSAvoidprotein identification and isolation
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The bacterial host cell automatically expresses and presents the bait protein on its surface through the Tat secretion pathway, and the prey protein is expressed intracellularly, eliminating the need for external protein preparation, identification, and isolation steps

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system combines multiple functions into a single living cell: protein expression, protein folding, surface presentation, and interaction detection all occur within the same bacterial host, eliminating the need for separate steps for each function

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

3Productivity

If traditional protein arrays are used, then protein interactions can be analyzed, but the preparation requires purification and the process is not high-throughput

Engineering Contradiction:
Improvehigh-throughput analysisVSAvoidarray preparation
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The bacterial host cell autonomously performs protein expression, folding, and surface presentation through the Tat pathway, eliminating manual purification and array preparation steps, thereby enabling high-throughput analysis without complex manufacturing procedures

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the state of the protein from purified and immobilized on solid supports to naturally presented on living bacterial cell surfaces, which fundamentally simplifies the preparation process and enables high-throughput screening by allowing direct use of bacterial cultures

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If proteins are immobilized on arrays, then binding events can be detected, but the proteins lose their ability to interact with other proteins

Engineering Contradiction:
Improvedetection of binding eventsVSAvoidprotein interaction ability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces artificial immobilization on solid supports with natural presentation on living bacterial cell surfaces through the Tat pathway, which maintains proteins in their native, functional state and preserves their ability to interact with other proteins

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

Solution Approach 2:

The living bacterial cell maintains the protein in its native environment with proper folding and post-translational modifications, preserving interaction ability while still enabling detection of binding events through the growth-based readout

Inventive Principle:
Principle #25Self-service

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 fast, reliable, and high-throughput analysis of protein-protein interactions, retaining protein functionality and allowing for efficient identification and characterization of interacting proteins and potential drug compounds, while simplifying the screening process.

Implementation Method 1

a first fusion protein comprising a Tat signal sequence and the first test polypeptide

Methodology Applied
Scientific EffectTat signal sequence-mediated protein export:

Data Source

PatentEP1917347B1Compositions and methods for analyzing protein interactions
Publication Date: 2015.10.07 CORNELL RES FOUNDATION INC
  • EP1917347B1 patent drawingFigure 1
  • EP1917347B1 patent drawingFigure 2A~2C
  • EP1917347B1 patent drawingFigure 3A~3B

AI summary

The present invention relates to compositions and methods for analyzing and modulating (e.g., enhancing or inhibiting) protein-protein interactions. In particular, compositions and methods of the present invention find use in identifying, reconstituting and characterizing protein-protein interactions, identifying binding subunits, and drug screening. The methods and compositions of the invention may also be used to identify agents that may agonize or antagonize a protein-protein interaction (e.g., using test compounds).