Brilliant blue R dye is capable of suppressing amyloid fibril formation of lysozyme.

Amyloid fibril formationis associated with an array of degenerative diseases. While no real cure is currently available, evidence suggests that suppression of amyloidfibrillogenesis is an effective strategy toward combating these diseases. Brilliant blue R (BBR), a disulfonatedtriphenylmethane compound, has been shown to interact with fibril-forming proteins but exert different effects on amyloid fibrillogenesis. These inconsistent findings prompted us to further evaluate BBR's effect on the inhibition/suppresion of protein fibrillogenesis. Using129-residue hen lysozyme, which shares high sequence homology to human lysozyme associated with hereditary non-neuropathic systemic amyloidosis, as a model, this study is aimed atthoroughly examining the influence of BBR on the in vitro protein fibrillogenesis. We first showed that BBR dose-dependently attenuated lysozyme fibril formation probably by affecting the fibril growth rate, withthe value of IC50 determined to be ~4.39 μM.Next, we employedtryptophan fluorescence quenching method to determine the binding constant and number of binding site(s) associated with BBR-lysozyme binding. In addition, we further conducted molecular docking studies to gain a better understanding of the possible binding site(s) and interaction(s) between lysozyme and BBR. We believe some of the information and/or knowledge concerning the structure-function relationship associated with BBR's suppressing activity obtained here can be applied forthe future work in the subject matter related withthe therapeutic strategies for amyloid diseases.