Directed assembly of functional light harvesting antenna complexes onto chemically patterned surfaces

Area of Science:

• Biophysics
• Biochemistry
• Materials Science

Background:

• Photosynthetic membrane proteins play crucial roles in energy conversion.
• Controlled assembly of proteins is essential for developing biomimetic systems.
• Rhodobacter sphaeroides proteins LH1 and LH2 are key components of the photosynthetic apparatus.

Purpose of the Study:

• To achieve directed assembly of LH1 and LH2 proteins onto chemically patterned substrates.
• To investigate the selective binding of these proteins based on surface chemistry.
• To confirm the retention of native optical properties after assembly.

Main Methods:

• Utilizing nanoimprint lithography to create chemically patterned glass substrates with distinct self-assembled monolayers (SAMs).
• Employing atomic force microscopy (AFM) to visualize and quantify protein assembly.
• Using a hybrid scanning probe and fluorescence microscope to assess protein optical signatures.

Main Results:

• Successfully demonstrated the directed assembly of LH1 and LH2 protein complexes onto patterned substrates.
• Observed selective attachment of protein complexes to amino-terminated SAMs via electrostatic interactions.
• Confirmed that the assembled proteins maintained their native optical signatures, indicating functional integrity.

Conclusions:

• Directed assembly of photosynthetic proteins is achievable on chemically patterned surfaces.
• Electrostatic interactions play a key role in the selective binding of these proteins.
• The developed method allows for the creation of functional protein arrays with preserved optical properties.