User:Josie N. Harmon/Sandbox 1
From Proteopedia
Xanthine Oxidase in Complex with 6-Mercaptopurine
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Xanthine oxidase is characterized as a molybdenum containing enzyme that catalyzes the hydroxylation of a sp2 hybrized carbon in a broad range of aromatic heterocycles and aldehydes. The crystal structure of the bovine xanthine oxidase complex contains two active sites with varying intrinsic activity. In eukaryotes xanthine oxidases exist as homodimers with each monomer containing four redox-active sites. The crystalline structure of a xanthine oxidase offers a better view of the active molybdenum center, , and FAD.
6-Mercaptopurine is classified as a cytotoxic chemotherapy agent frequently used to treat acute lymphoblastic leukemia (ALL). The 6-mercaptopurine complex consists of a total of encased within the xanthine oxidase protein complex. These ligands include: Flavin-Adenine Dinucleotide, , Dioxothiomolybdenum (VI) ion , Phosphonic acidmono-(2-amino-5,6-dimercapto- 4-oxo-3,7,8A,9,10,10A-hexahydro-4H-8-oxo- 1,3,9,10-tetraaza-anthracen-7-ylmethyl)ester , and
A of the structure is represented with purple arrows representing the alpha helix structures and gold arrows representing the beta strand structures. The of the protein backbone can also be noted by the blue arrows on the structure. The helix consists of various protein residues and an between two aromatic residues is shown here, with the blue structure representing phenylalanine and the green structure representing tryptophan.
