Supported Biomembrane Systems Incorporating Multiarm Polymers and Bioorthogonal Tethering

TL;DR

This paper presents a method to create stable supported biomembranes using multiarm polymers and bioorthogonal chemistry to preserve membrane protein function.

Contribution

The novel approach combines multiarm PEG and bioorthogonal tethering to build functional supported biomembranes on microspheres.

Findings

4-arm-PEG20,000-NH2 provided optimal lateral diffusivity and coverage in supported biomembranes.

The system showed low nonspecific binding of proteins and antibodies.

Membrane structures were confirmed using advanced imaging and FRAP techniques.

Abstract

To functionalize
interfaces with supported biomembranes and membrane
proteins, the challenge is to build stabilized and supported systems
that mimic the native lipid microenvironment. Our objective is to
control substrate-to-biomembrane spacing and the tethering chemistry
so proteoliposomes can be fused and conjugated without perturbation
of membrane protein function. Furthermore, the substrates need to
exhibit low protein and antibody nonspecific binding to use these
systems in assays. We have employed protein orthogonal coupling schemes
in concert with multiarm poly(ethylene glycol) (PEG) technology to
build supported biomembranes on microspheres. The lipid bilayer structures
and tailored substrates of the microsphere-supported biomembranes
were analyzed via flow cytometry, confocal fluorescence, and super-resolution
imaging microscopy, and the lateral fluidity was quantified using
fluorescence recovery after photobleaching (FRAP) techniques. Under
these conditions, the 4-arm-PEG20,000-NH2 based
configuration gave the most desirable tethering system based on lateral
diffusivity and coverage.

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