ENTRY       EC 1.1.1.204
NAME        Xanthine dehydrogenase
CLASS       Oxidoreductases
            Acting on the CH-OH group of donors
            With NAD+ or NADP+ as acceptor
SYSNAME     Xanthine:NAD+ oxidoreductase
REACTION    Xanthine + NAD+ + H2O = Urate + NADH
SUBSTRATE   Xanthine
            NAD+
            H2O
PRODUCT     Urate
            NADH
COMMENT     Acts on a variety of purines and aldehydes. The animal enzyme can
            be interconverted to EC 1.1.3.22 (the oxidase form). That from
            liver exists in vivo mainly in the dehydrogenase form, but can
            be converted into EC 1.1.3.22 by storage at -20C, by treatment
            with proteolytic agents or organic solvents, or by thiol reagents
            such as Cu2+, N-ethylmaleimide or 4-hydroxy-mercuribenzoate.
            The effect of thiol reagents can be reversed by thiols such as
            1,4-dithio-erythritol. EC 1.1.1.204 can also be converted into
            EC 1.1.3.22 by EC 1.8.4.7 in the presence of oxidized glutathione.
            In other animal tissues the enzyme exists almost entirely as
            EC 1.1.3.22, but can be converted into the dehydrogenase form
            by 1,4-dithioerythritol. Formerly EC 1.2.1.37.
PATHWAY     PATH: MAP00230  Purine metabolism
MOTIF       PS: PS00197  C-{C}-{C}-[GA]-{C}-C-[GAST]-{cpdhtmEKRHFYW}-C
            PS: PS00559  [GA]-x(3)-[KRNQHT]-x(11,14)-[LIVMFYWS]-x(8)-[LIVMF]-x-
                         C-x(2)-[DEN]-R-x(2)-[DE]
GENES       HSA: XDH(Hs.250)
DBLINKS     University of Geneva ENZYME DATA BANK: 1.1.1.204
            WIT (What Is There) Metabolic Reconstruction: 1.1.1.204
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