Switching of Recognition First and Reaction First Mechanisms in Host–Guest Binding Associated with Chemical Reactions

Slowing down interactions between host and guest

30 June 2020

New insights into ‘host–guest’ chemistry could benefit drug-delivery vehicles and materials that mop up toxic metals.

In systems where a large host molecule (such as an enzyme) interacts with a small molecular guest, the binding of the guest often goes hand in hand with a structural or chemical reaction in the host. But this process typically occurs too quickly to tell whether the binding of the guest induces the host’s reaction (‘recognition first’) or whether the reaction precedes binding (‘reaction first’).

Now, four researchers, all at Kanazawa University in Japan, have developed a slow-binding host–guest system, which enabled them to probe which of the two mechanisms occurs when the host and a metal guest come together. By alternating the guest metal used, they were even able to switch the system from a recognition-first to a reaction-first mechanism.

This finding will help design uptake/release systems that are time dependent, such as drug-delivery systems.

Supported content

References

1. Journal of the American Chemical Society 141, 15597–15604 (2019). doi: 10.1021/jacs.9b06926