Thermodynamic versus kinetic basis for the high conformational stability of nanobodies for therapeutic applications

Abstract

Single domain nanobodies (NB) are powerful tools for biotechnological and therapeutic applications. They strongly bind to their targets and are very stable. Early studies showed that NB unfolding is reversible and can be analyzed by equilibrium thermodynamics whereas more recent studies focused on their kinetic stability in very harsh conditions, far from storage or physiological temperatures (4-37{degrees}C). Here we reinforce the thermodynamic view in which a simple two-state denaturation model is applicable. We found that thermal stability of NB actually reflect thermodynamic stabilities in wide range of temperatures (18-100{degrees}C). We also modeled their structure observing subtle differences. We expect that our approach will be helpful to improve our capacity to enhance structure-function-stability relationships of NB.