Histochemical localization of mushroom tyrosinase in whole tissue sections on nitrocellulose

Mushrooms were cut into vertical and horizontal sections. These sections were blotted onto nitrocellulose sheets and the sheets were then stained for tyrosinase using L-dopa. Tyrosinase was localized throughout the mushroom tissues but more enzyme was located in the epidermis of the cap, the gill region, and the stipe. Preincubation of the nitrocellulose sheets in specific inhibitors of tyrosinase completely blocked enzyme staining, suggesting that the enzyme stained areas on the nitrocellulose blots were regions of tyrosinase activity. Immunochemical localization of tyrosinase was similar to that observed by histochemical staining. Nitrocellulose blotting of mushrooms allows localizations of enzyme at the whole tissue level and may be useful for other enzymes in mushrooms as well.