Supported Biomembrane Systems Incorporating Multiarm Polymers and Bioorthogonal Tethering

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Biophysics

Background:

• Functionalizing interfaces with supported biomembranes and membrane proteins requires mimicking the native lipid microenvironment.
• Stabilized systems are crucial for controlling substrate-biomembrane spacing and tethering chemistry.
• Low nonspecific binding is essential for assay applications.

Purpose of the Study:

• To develop a method for creating supported biomembranes on microspheres.
• To control substrate-to-biomembrane spacing and tethering chemistry for proteoliposome fusion.
• To achieve low nonspecific binding for enhanced assay performance.

Main Methods:

• Employed protein orthogonal coupling schemes with multiarm poly(ethylene glycol) (PEG) technology.
• Utilized microspheres as substrates for building supported biomembranes.
• Analyzed lipid bilayer structures and substrates using flow cytometry, confocal fluorescence, and super-resolution microscopy.
• Quantified lateral fluidity via fluorescence recovery after photobleaching (FRAP).

Main Results:

• Successfully built supported biomembranes on microspheres.
• The 4-arm-PEG20,000-NH2 configuration demonstrated the most desirable tethering system.
• Achieved optimal lateral diffusivity and coverage with the selected PEGylation strategy.
• Demonstrated low nonspecific binding properties.

Conclusions:

• The developed microsphere-supported biomembranes effectively mimic native lipid microenvironments.
• The 4-arm-PEG-NH2 tethering system provides a robust platform for membrane protein studies.
• This approach facilitates proteoliposome fusion and conjugation without compromising membrane protein function.