Structural Transitions and Enzymatic Function of Ribonuclease A Encapsulated in Transparent Porous Silica Gel
Transparent porous silica gel encapsulating ribonuclease A (RNase A) in nanoscale pores was prepared on the wall of a quartz cell. The UV and CD spectral changes upon heating showed that the protein unfolds in the pores with apparent heat denaturation temperatures (Tm) at 60 to 64 °C, which are slig...
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| Published in: | Bulletin of the Chemical Society of Japan Vol. 83; no. 8; pp. 935 - 941 |
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| Main Authors: | , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Tokyo
The Chemical Society of Japan
15-08-2010
Chemical Society of Japan |
| Online Access: | Get full text |
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| Summary: | Transparent porous silica gel encapsulating ribonuclease A (RNase A) in nanoscale pores was prepared on the wall of a quartz cell. The UV and CD spectral changes upon heating showed that the protein unfolds in the pores with apparent heat denaturation temperatures (Tm) at 60 to 64 °C, which are slightly lower than that in solution. The unfolding was irreversible due probably to strong interaction of the unfolded species with the surface of the pores upon prolonged treatment at high temperatures. However, when the gel was subjected to repeated temperature-jump experiments between 40 and 75 °C, RNase A reversibly unfolded and refolded in the pores. The unfolding was not apparently decelerated but the refolding was remarkably slowed. The protein refolded in the porous gel exhibited enzymatic activity toward cytidine 2′,3′-cyclic monophosphate (c-CMP), indicating that small molecules, such as c-CMP and its hydrolyzed species, can go through the holes of the silica gel. These results demonstrated not only that the wet porous gel is useful for the heat denaturation study of proteins but also that the gel encapsulating a protein can be applied as a soft material with enzymatic function. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0009-2673 1348-0634 1348-0634 |
| DOI: | 10.1246/bcsj.20090337 |