1.8.1.18: NAD(P)H sulfur oxidoreductase (CoA-dependent)
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For detailed information about NAD(P)H sulfur oxidoreductase (CoA-dependent), go to the full flat file.
Reaction
Synonyms
CoA-dependent NAD(P)H: elemental sulfur (S0) oxidoreductase, coenzyme A-dependent NADPH sulfur oxidoreductase, NAD(P)H-dependent sulfur reductase, NAD(P)H: S0 oxidoreductase, NADPH NSR, NSR, PF1186, S(0) reductase, TK1186, TK1299
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1.8.1.18 NAD(P)H sulfur oxidoreductase (CoA-dependent)Advanced search results
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Substrates Products on EC 1.8.1.18 - NAD(P)H sulfur oxidoreductase (CoA-dependent)
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SUBSTRATE 
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
sulfur + NADH + H+
hydrogen sulfide + NAD+
colloidal sulfur generated from polysulfide is a better substrate than the elemental sulfur. The sulfur reductase activity requires anaerobic conditions (the product sulfide is oxidized by oxygen)
-
-
?
sulfur + NADPH + H+
hydrogen sulfide + NADP+
colloidal sulfur generated from polysulfide is a better substrate than the elemental sulfur. The sulfur reductase activity requires anaerobic conditions (the product sulfide is oxidized by oxygen)
-
-
?
polysulfide(n) + NADPH + H+
hydrogen sulfide + polysulfide(n-1) + NADP+
-
-
-
?
polysulfide(n) + NADPH + H+
hydrogen sulfide + polysulfide(n-1) + NADP+
B2BSJ7; B2BSJ6; B2BSJ5; B2BSK0
NADH can not replace NADPH, the purified recombinant enzyme catalyzes the reduction of polysulfide with NADPH as an electron donor and it also reduces oxygen
-
-
?
polysulfide(n) + NADPH + H+
hydrogen sulfide + polysulfide(n-1) + NADP+
B2BSJ7; B2BSJ6; B2BSJ5; B2BSK0
NADH can not replace NADPH, the purified recombinant enzyme catalyzes the reduction of polysulfide with NADPH as an electron donor and it also reduces oxygen
-
-
?
sulfur + NAD(P)H + H+
hydrogen sulfide + NAD(P)+
the rate of sulfide production from colloidal sulfur is linear (up to 10 min) suggesting that this is the true substrate for the enzyme. A lag phase in sulfide production would be expected if polysulfide, which is generated by the reaction of sulfide with elemental sulfur, is the natural substrate. A less-than-twofold increase in activity is observed, both at pH 7.0 and at pH 9.0, when polysulfide (11 mM) is used as the substrate compared to when elemental sulfur (6.4 g/liter) is used. Polysulfide is stable at pH 8 and readily dissociates to colloidal sulfur and sulfide at neutral pH. A much greater stimulation of activity would be observed if polysulfide is the preferred substrate, particularly at the higher pH
-
-
?
sulfur + NAD(P)H + H+
hydrogen sulfide + NAD(P)+
-
-
-
?
sulfur + NAD(P)H + H+
hydrogen sulfide + NAD(P)+
a catalytic cycle of TK1299 is proposed suggesting that CoA-SH acts to solubilize S(0) by forming CoA persulfides, followed by reduction of an enzyme-S-S-CoA intermediate produced after both enzymatic and non-enzymatic evolution of H2S from the CoA persulfide, with NADPH as an electron donor
-
-
?
additional information
?
-
PF1186 is formerly proposed to function as a NAD(P)H-dependent CoA-S-S-CoA reductase (CoADR) gene (EC 1.8.1.14). The specific activity for CoA-S-S-CoA reduction (0.006 mol CoA-S-S-CoA reduced/min/mg) is about 20fold lower than the activity that this enzyme exhibits in the S(0) reduction assay. The formeryly reported CoADR activity represents only a partial reaction of its true physiological function, which is now proposed to be CoA-dependent S(0) reduction
-
-
?
additional information
?
-
-
PF1186 is formerly proposed to function as a NAD(P)H-dependent CoA-S-S-CoA reductase (CoADR) gene (EC 1.8.1.14). The specific activity for CoA-S-S-CoA reduction (0.006 mol CoA-S-S-CoA reduced/min/mg) is about 20fold lower than the activity that this enzyme exhibits in the S(0) reduction assay. The formeryly reported CoADR activity represents only a partial reaction of its true physiological function, which is now proposed to be CoA-dependent S(0) reduction
-
-
?
