Journal
INTERNATIONAL JOURNAL OF BIOCHEMISTRY & CELL BIOLOGY
Volume 38, Issue 11, Pages 1986-1994Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.biocel.2006.05.012
Keywords
protein-protein interactions; macromolecular crowding; superoxide dismutase; thermodynamics; xanthine oxidase
Categories
Ask authors/readers for more resources
Physiological medium constitutes a crowded environment that serves as the field of action for protein-protein interaction in vivo. Measuring protein-protein interaction in crowded solutions can mimic this environment. Here we report the application of fluorescence spectroscopy and resonant mirror biosensor to investigate the interactions of bovine milk xanthine oxidase and bovine erythrocyte copper, zinc-superoxide dismutase in crowded solutions. Four nonspecific high molecular mass crowding agents, poly(ethylene glycol) 2000 and 20,000, Ficoll 70, and dextran 70, and one low molecular mass compound, glycerol, are used. Superoxide dismutase shows a strong and macromolecular crowding agent concentration-dependent binding affinity to xanthine oxidase. Addition of high concentrations of such high molecular mass crowding agents increases the binding constant remarkably and thus stabilizes superoxide dismutase activity, compared to those in the absence of crowding agents. In contrast, glycerol has little effect on the binding constant and decreases superoxide dismutase activity over the same concentration range. Such a pattern suggests that the enhancing effects of polymers and polysaccharides on the binding are due to macromolecular crowding. Taken together, these results indicate that macromolecular crowding enhances the binding of superoxide dismutase to xanthine oxidase and is favorable to the function of superoxide dismutase. (c) 2006 Elsevier Utd. All fights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available