we performed mushroom tyrosinase assay, and it all worked, our compund was able to inhibit tyrosinase, but when using human tyrosinase assay, the compound gave no inhibition, any ideas?
The enzyme tyrosinase, involved in the synthesis of melanin, is different in terms of the sequence of amino acids that constitute it, depending on the source from which it is acquired. In the work published by Halaouli et al., (2006) it can be observed how the enzyme from fungi (A. bisporus) retains a low homology with that of mouse (M. musculus) and with that of human (H. sapiens ) (can also be seen in van Gelder et al., 1997, García-Borrón et al., 2002, Wang et al., 2006).
Additionally, it has been reported that the inhibition by bioactive compounds of the tyrosinase enzyme from fungi does not have a direct correlation with the tyrosinase inhibition of mouse melanoma cells (Kubo et al., 2007).
One question, in both cases are you measuring the inhibition of diphenolase activity?