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Literature summary for 1.17.3.2 extracted from

  • Hadizadeh, M.; Keyhani, E.; Keyhani, J.; Khodadadi, C.
    Functional and structural alterations induced by copper in xanthine oxidase (2009), Acta Biochim. Biophys. Sin., 41, 603-617.
    View publication on PubMed
Search for more literature for 1.17.3.2

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
 additional information steady-state kinetics study of enzyme activity in the presence of Cu2+ and with different pre-incubation times, KM values of 0.0096-0.020 mM, overview Bos taurus

Localization

Localization Comment Organism GeneOntology No. Textmining
extracellular secretion to milk Bos taurus
-
-

Metals/Ions

Metals/Ions Comment Organism Structure
Cu2+ Cu2+ either stimulates or inhibits xanthine oxidase activity, depending on metal concentration (inhibition above 0.7 mM) and pre-incubation length, the latter also determining the inhibition type. Cu2+-enzyme complex formation is characterized by modifications in xanthine oxidase electronic absorption bands, intrinsic fluorescence, and alpha-helical and beta-sheet content. Apparent dissociation constant values imply high- and low-affinity Cu2+ binding sites in the vicinity of the enzyme's reactive centers, Cu2+ binding to high-affinity sites causes alterations around xanthine oxidase molybdenum and flavin adenine dinucleotide centers, changes in secondary structure, and moderate activity inhibition, binding to low affinity sites causes alterations around all xanthine oxidase reactive centers including FeS, changes in tertiary structure as reflected by alterations in spectral properties, and drastic activity inhibition. Stimulation is attributed to transient stabilization of xanthine oxidase optimal conformation. Potential role of copper in the regulation of xanthine oxidase activity, binding kinetics, detailed overview Bos taurus

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
xanthine + O2 + H2O Bos taurus
-
 urate + H2O2
-
 ?

Organism

Organism UniProt Comment Textmining
Bos taurus
-
-
-

Source Tissue

Source Tissue Comment Organism Textmining
commercial preparation
-
 Bos taurus
-
milk
-
 Bos taurus
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
xanthine + O2 + H2O
-
 Bos taurus urate + H2O2
-
 ?

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.5
-
 assay at Bos taurus

General Information

General Information Comment Organism
metabolism xanthine oxidase, a key enzyme in purine metabolism, produces reactive oxygen species causing vascular injuries and chronic heart failure Bos taurus