Supramolecular tandem assay for tyrosinase based on cucurbit[8]uril induced peptide inclusion

Many fluorometric methods have been developed for detecting tyrosinase activity, yet many of them require the sophisticated synthesis of relatively complex fluorescent molecules. Here, we report the utilization of a label-free supramolecular tandem assay for measuring tyrosinase activity based on an easily available reporter pair. Cucurbit[8]uril (CB[8]) can bind with thioflavin-T (ThT) and increase its fluorescence intensity, while the tripeptides YLA and Dopa-LA can decrease the fluorescence intensity of CB[8]-ThT complex. YLA and Dopa-LA can be oxidized by tyrosinase, and the products have lower binding affinity with CB[8], leading to an increase of fluorescence in the intensity of CB[8]-ThT-YLA or Dopa-LA. We were able to continuously monitor tyrosinase activity with CB[8]-ThT-YLA or Dopa-LA.