Shape effect on non-covalent dimer stability using classic scaled particle theory

The shape of two non-covalent dimers formed by different variants of the B1 domain of protein G plays an important role for their stability in water and aqueous solutions [Proc. Natl. Acad. Sci. U.S.A. 115 (2018) 10965]. I demonstrate how much the stabilization afforded by the decrease in solvent-excluded volume upon association depends on the shape of the dimers in water and aqueous sugar solutions, using classic scaled particle theory. There is a strong dependence upon the decrease in water accessible surface area associated with dimer formation, whose general significance deserves attention.