Abstract

During the specific recognition of some proteins, the structure of the active site changes from disorder to order. The flexible naphthocage (NC) in our group also has similar behavior. In the free naphthocage without guests, the naphthyl group flips rapidly and multiple conformations exist. After binding with the guest, the complexes of two specific conformations are formed. These two conformations are slowly interconverted at room temperature. Through the process of dissociation-conformational change-binding, they self-adapted to select the most suitable conformation. Its kinetic rate constants are related to thermodynamic binding constants. The energy barrier of the flexible macrocycle is relatively uncontrollable and should be more flexible for different guests in theory, but in our system, it is relatively controllable, which builds a bridge between kinetics and thermodynamics.