Amphipathic Polymer Lipid Nanodiscs for Detergent-Free Membrane Protein Extraction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for isolating and characterizing membrane proteins are hindered by the use of detergents, which lead to protein inactivation and sample aggregation, and existing nanodiscs, such as those based on membrane scaffold proteins, peptides, and copolymers, are limited by size restrictions, stability issues, and high production costs.

Innovation Solution

The development of lipid nanodiscs formed from a lipid bilayer with a hydrophobic edge encircled by a polymer comprising a monomeric unit with a pendant hydrophobic group and a monomeric unit with a backbone hydrophilic group, allowing for detergent-free extraction and characterization of membrane proteins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If detergents are used to extract membrane proteins from native environment, then extraction efficiency is improved, but protein inactivation and sample aggregation occur

Engineering Contradiction:

Improveextraction efficiencyVSAvoidprotein stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces amphipathic polymers as intermediary molecules that mediate between the hydrophobic membrane proteins and the aqueous environment. These polymers contain both hydrophobic groups (for interacting with membrane proteins) and hydrophilic groups (for interacting with water), enabling detergent-free extraction while maintaining protein stability and native conformation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If membrane scaffold protein-based nanodiscs are used, then good mimicry of membrane is achieved, but detergent use is still required and production cost increases

Engineering Contradiction:

Improvemembrane mimicry qualityVSAvoidproduction cost and complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, difficult-to-produce membrane scaffold proteins with inexpensive, easily synthesized amphipathic polymers. These polymers can be produced through simple chemical synthesis rather than complex biological expression systems, significantly reducing production costs while eliminating the need for detergent use in nanodisc formation.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If peptide-based nanodiscs are used, then nanodisc formation is achieved, but stability issues occur and biophysical measurements are interfered with

Engineering Contradiction:

Improvenanodisc formation capabilityVSAvoidnanodisc stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent employs composite amphipathic polymers with carefully designed combinations of hydrophobic and hydrophilic groups. This composite structure provides both the stability needed for nanodisc formation and the optical properties required for biophysical measurements, overcoming the limitations of pure peptide-based systems that interfere with measurement techniques.

Inventive Principle:

Principle #40Composite materials

4Ease of manufacture

If copolymer-based nanodiscs are used, then nanodisc formation is achieved, but size range is restricted and tolerance to divalent metal ions and pH varies

Engineering Contradiction:

Improvenanodisc formationVSAvoidsize range and environmental tolerance

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent designs amphipathic polymers with dynamic and adjustable properties, including variable chain lengths, different ratios of hydrophobic to hydrophilic groups, and flexible molecular architectures. This dynamic design allows the polymers to adapt to different nanodisc sizes and maintain stability across a wide range of environmental conditions, including varying pH and presence of divalent metal ions.

Inventive Principle:

Principle #15Dynamics

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

These lipid nanodiscs enable the stable extraction and characterization of membrane proteins without detergent use, offering a wide size range and pH tolerance, and are cost-effective, suitable for various biophysical techniques like circular dichroism and fluorescence spectroscopy.

Implementation Method 1

the polymer comprises a first monomeric unit having a pendant hydrophobic group and a second monomeric unit having a backbone hydrophilic group

Methodology Applied

Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

a polymer encircling the hydrophobic edge of the lipid bilayer, wherein the polymer comprises a first monomeric unit having a pendant hydrophobic group and a second monomeric unit having a backbone hydrophilic group

Methodology Applied

Scientific EffectAmphiphilic interaction: Amphiphiles

Data Source

PatentUS11813358B2Lipid nanodisc formation by polymers having a pendant hydrophobic group

Publication Date: 2023.11.14 THE RGT UNIV OF MICHIGAN

AI summary

The disclosure generally relates to lipid nanodiscs, in particular to lipid nanodiscs formed from polymers. A lipid nanodisc according to the disclosure includes a lipid bilayer having a first hydrophilic face and a second hydrophilic face opposing the first hydrophilic face, and a hydrophobic edge between the opposing hydrophilic faces, and a polymer encircling the hydrophobic edge of the lipid bilayer. The polymer includes a first monomeric unit having a pendant hydrophobic group and a second monomeric unit having a backbone hydrophilic group. Methods of making and characterizing the lipid nanodiscs are also disclosed.