Sau, Apurba Kumar ; Mondal, Madhu Sudan ; Mitra, Samaresh (1998) Reaction of milk xanthine oxidase with o-phenanthroline and 1,7-dimethylxanthine: a mechanistic study Journal of Chemical Society, Dalton Transactions (24). pp. 4173-4177. ISSN 0300-9246
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Abstract
The kinetics of the reaction of milk xanthine oxidase (XO) with o-phenanthroline and 1,7-dimethylxanthine are investigated by optical and circular dichroism (CD) spectroscopic techniques. o-Phenanthroline and 1,7-dimethylxanthine are observed to react with XO, resulting in a slow decrease in the absorbance and CD signals of the enzyme. The results suggest the existence of a multi-binding mechanism in the reaction of XO with o-phenanthroline with two molecules of the substrate binding to one molecule of the enzyme. However, 1,7-dimethylxanthine binds reversibly with the enzyme with 1 : 1 stoichiometry. The kinetic effect experienced individually by the flavin adenine dinucleotide (FAD) chromophore of XO has been separately resolved, and shows that at least one molecule of o-phenanthroline may bind near the FAD centre of the enzyme. 1,7-Dimethylxanthine is expected to bind to the molybdenum centre in analogy with xanthine.
Item Type: | Article |
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Source: | Copyright of this article belongs to Royal Society of Chemistry. |
ID Code: | 20170 |
Deposited On: | 20 Nov 2010 14:55 |
Last Modified: | 17 May 2016 04:33 |
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