Creation of stable water-free antibody based protein liquids

Abstract

Antibodies represent highly specific and high binding affinity biomolecular recognition elements for diagnostic assays, biosensors, and therapeutics, but are sensitive to denaturation and degradation. Consequently, the combination of existing in a hydrated state with a large and complex biomolecular structure results in loss of antibody-antigen binding, limited shelf-life, and decreased sensor response over time and under non-optimal conditions. The development and use of water-free protein liquids has led to stabilization of labile biomolecules, solvents for biotransformation reactions, and formation of new bio-composites with incompatible materials. Here, we exploit the polycationic nature of modified antibodies and their ability to form ion pairs for the conversion of primary Immunoglobulin G antibodies into stable protein liquids that retained more than 60% binding activity after repeated heating up to 125 °C, and demonstrate compatibility with thermoplastics.