کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8331027 | 1540241 | 2015 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
DNA template-assisted inhibition of tyrosinase activity
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موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Enzyme-mediated polymerization reactions have been widely studied in the context of DNA template-assisted reactions. We have recently highlighted the ability of DNA templates to modulate enzyme-catalyzed single-step transformations. In this work, we focus on the intramolecular transformation of L-dopa catalyzed by enzyme tyrosinase and report a novel role of DNA templates in inhibition of the enzyme. The kinetics of mushroom tyrosinase monitored by UV-visible spectroscopy reveals significant decrease in the enzyme's efficiency in the presence of short double-stranded DNA molecules. KM of tyrosinase is found to increase by nearly 1.8-fold, implying a lower affinity of the enzyme for L-dopa, whereas Vmax is only marginally affected. The mode of inhibition is assessed to be a mixed mode with kinetic constants of inhibition in the micromolar range. Further, in the presence of cinnamic acid and DNA duplexes, the KM of tyrosinase increases nearly 3.5-fold, whereas Ki and Kiâ² are lowered by an order of magnitude. These results are a corollary of the known influence of substrate-template interactions and greater local substrate concentrations on enzyme activity and expand the paradigm with respect to use of DNA templates in enzyme-catalyzed reactions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 79, August 2015, Pages 278-283
Journal: International Journal of Biological Macromolecules - Volume 79, August 2015, Pages 278-283
نویسندگان
Pallavi Chilka, Sarah Phillips, Bhaskar Datta,