Mushroom Tyrosinase: Six Isoenzymes Catalyzing Distinct  Reactions

Chembiochem. 2024 Feb 22:e202400050. doi: 10.1002/cbic.202400050. Online ahead of print.ABSTRACT"Mushroom tyrosinase" from the common button mushroom is the most frequently used source of tyrosinase activity, both for basic and applied research. Here, the complete tyrosinase family from Agaricus bisporus var. bisporus (abPPO1-6) was cloned from mRNA and expressed heterologously using a single protocol. All six isoenzymes accept a wide range of phenolic and catecholic substrates, but display pronounced differences in their specificity and enzymatic reaction rate. AbPPO3 ignores γ-l-glutaminyl-4-hydroxybenzene (GHB), a natural phenol present in mM concentrations in A. bisporus, while AbPPO4 processes 100 µM GHB at 4-times the rate of the catechol l-DOPA. All six AbPPOs are biochemically distinct enzymes fit for different roles in the fungal life cycle, which challenges the traditional concept of isoenzymes as catalyzing the same chemical reaction and varying only in secondary properties. Transferring this approach to other enzymes and organisms will greatly stimulate both the study of the in vivo function(s) of enzymes and the application of these highly efficient catalysts.PMID:38386893 | DOI:10.1002/cbic.202400050
Source: Chembiochem - Category: Biochemistry Authors: Source Type: research