Solvent-free liquid avidin as a step toward cold chain elimination

Area of Science:

• Biochemistry
• Materials Science
• Protein Engineering

Background:

• Therapeutic proteins and vaccines require strict temperature control (2-8°C) via the cold chain for distribution.
• The cold chain presents significant logistical and economic challenges for global healthcare access.

Purpose of the Study:

• To investigate surface engineering as a method to enhance the thermal stability of therapeutic proteins.
• To assess the impact of surface modification on protein structure, function, and long-term stability.

Main Methods:

• Utilized avidin as a model protein for surface engineering.
• Employed spectroscopic techniques (FTIR, CD, UV-Vis) and scattering methods (DLS, SAXS, WAXS) to analyze protein properties.
• Conducted temperature-dependent synchrotron radiation circular dichroism spectroscopy and accelerated aging studies.

Main Results:

• Modified avidin exhibited significantly increased thermal stability with a half denaturation temperature of 139.0°C.
• The modified protein demonstrated reversible unfolding and retained 90% of its folded state after heating below 100°C.
• Accelerated aging showed preserved secondary structure after 56 days at 40°C, equivalent to 160 days at 25°C.
• Ligand binding studies confirmed the functionality of the modified protein's binding site.

Conclusions:

• Surface engineering can dramatically improve the thermal stability of therapeutic proteins.
• This approach offers a potential solution to eliminate the cold chain requirement for protein-based therapeutics.
• The findings pave the way for wider global access to life-saving vaccines and treatments.