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http://nopr.niscpr.res.in/handle/123456789/15383| Title: | Reverse micelles as water property control system to investigate the hydration, superactivity and kinetics of invertase |
| Authors: | Singh, Anjana Dubey, R S |
| Issue Date: | Jun-2000 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Invertase, entrapped in hydrated reverse micelles of sodium bis (2-ethylhexyl) sulfosuccinate (Aerosol-OT, AOT) in isooctane showed 5.8 fold enhancement in its activity in comparison to the activity of invertase in bulk aqueous medium. Fluorescence spectra of the enzyme was examined as a function of Wo (molar ratio of water to surfactant) to monitor overall conformational changes associated with polarity changes due to the presence of tryptophan in these proteins. The degree of hydration required in terms of Wo for maximum activity of invertase was from 8 to 18. The pH/activity profile of the enzyme was bell shaped in the aqueous system with optimum pH of 5.0, whereas, within reverse micelles, maximum activity was near alkaline pH and the pH/activity profile approached a sigmoid shape. The activity increased within reverse micelles in presence of 1 to 400 mM NaCI whereas under similar NaCI concentration in the aqueous medium almost static level of enzyme activity was observed. In presence of MgCI2 the activity of invertase decreased in aqueous medium, whereas the activity was enhanced within reverse micelles. Under 50-1000 μMPb(NO3)2 almost similar level of invertase activity was observed in both aqueous medium and within reverse micelles. In presence of Cd(NO3 )2 (1000 μM) there was 38 per cent increase in enzyme activity within reverse micelles but there was no alteration in enzyme activity in aqueous medium. |
| Page(s): | 171-177 |
| ISSN: | 0975-0959 (Online); 0301-1208 (Print) |
| Appears in Collections: | IJBB Vol.37(3) [June 2000] |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJBB 37(3) 171-177.pdf | 1.55 MB | Adobe PDF | View/Open |
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