Thermodynamic Analysis of the Conformational Stability of a Single-Domain Therapeutic Antibody

Abstract

The stability of a new single-domain therapeutic antibody to the ErbB3 receptor was studied by fluorescence spectroscopy at different concentrations of a denaturing agent and temperatures. The analysis of experimental denaturation curves allowed us to build a complete thermodynamic model of unfolding and to determine all parameters of the transition: ΔG = 8.5 kcal mol^–1, T_m = 76°C, ΔH_m = 107 kcal mol^–1, ΔC_p = 1.8 kcal K^–1 mol^–1. The obtained data evidence the high stability of the antibody in a broad range of conditions, which is essential for further structural and functional studies and possible therapeutic application.