Structure and function of a flavin-dependent S-monooxygenase from garlic (Allium sativum).

ABSTRACT: Allicin is a component of the characteristic smell and flavor of garlic (Allium sativum). A flavin-containing monooxygenase (FMO) produced by A. sativum (AsFMO) was previously proposed to oxidize S-allyl-l-cysteine (SAC) to alliin, an allicin precursor. Here, we present a kinetic and structural characterization of AsFMO that suggests a possible contradiction to this proposal. Results of steady-state kinetic analyses revealed that AsFMO exhibited negligible activity with SAC; however, the enzyme was highly active with l-cysteine, N-acetyl-l-cysteine, and allyl mercaptan. We found that allyl mercaptan with NADPH was the preferred substrate-cofactor combination. Rapid-reaction kinetic analyses showed that NADPH binds tightly (K_D of ∼2 μm) to AsFMO

SUBMITTER: Valentino H 

PROVIDER: S-EPMC7415970 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature