The enzymatic activities of brain catechol-O-methyltransferase (COMT) and methionine sulphoxide reductase are correlated in a COMTVal/Metallele-dependent fashion

Aims The enzyme catechol-O-methyl transferase (COMT) plays a primary role in the metabolism of catecholamine neurotransmitters and is implicated in the modulation of cognitive and emotional responses. The best-characterized single nucleotide polymorphism (SNP) of the COMT gene consists of a valine (Val)-to-methionine (Met) substitution at codon 108/158. The Met-containing variant confers a marked reduction in COMT catalytic activity. We recently showed that the activity of recombinant COMT is positively regulated by the enzyme Met sulfoxide reductase (MSR), which counters the oxidation of Met residues of proteins. The current study was designed to assess whether brain COMT activity may be correlated to MSR in an allele-dependent fashion.