Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations]
Background: Human aldose reductase (hAR) is the first and rate-limiting enzyme of the polyol pathway. For the development of secondary complications of diabetes in chronic hyperglycemic conditions, one of the critical factors is the increased flux of glucose through the polyol pathway. Due to this...
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| Format: | Article |
| Language: | English |
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F1000 Research Ltd
2019-11-01
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| Series: | F1000Research |
| Online Access: | https://f1000research.com/articles/8-564/v2 |
| _version_ | 1828289677682016256 |
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| author | Gurprit Sekhon Ranvir Singh |
| author_facet | Gurprit Sekhon Ranvir Singh |
| author_sort | Gurprit Sekhon |
| collection | DOAJ |
| description | Background: Human aldose reductase (hAR) is the first and rate-limiting enzyme of the polyol pathway. For the development of secondary complications of diabetes in chronic hyperglycemic conditions, one of the critical factors is the increased flux of glucose through the polyol pathway. Due to this clinical implication, hAR attracted considerable attention from the drug discovery perspective. In spite of extensive characterization in the context of biochemical and structural aspects, we know very little about the unfolding behavior of hAR. This study reports equilibrium unfolding studies of hAR. Methods: We carried out thermal denaturation and chemical-induced equilibrium unfolding studies of hAR monitored by circular dichroism and fluorescence spectroscopy. Results: Thermal denaturation studies presented a classical picture of two-state unfolding from native to the denatured state. The data was used to derive thermodynamic parameters and study the thermostability of hAR. Chemical induced equilibrium unfolding studies led us to discover an intermediate state, which gets populated at 3.5-4.0 M and 0.7-2.0 M of urea and GuHCl, respectively. Thermodynamic parameters derived from chemical-induced unfolding are in agreement with those obtained from thermal denaturation of hAR. Conclusion: This study revealed that aldose reductase unfolds from native to the unfolded state via an intermediate. Assessment of the thermodynamic stability of native, intermediate, and unfolded states shows that significant energy barriers separate these states, which ensures the cooperativity of unfolding. As hAR functions in cells that are under osmotic and oxidative stress, these in vitro findings may have implications for its native conformation under the physiological state. |
| first_indexed | 2024-04-13T10:24:51Z |
| format | Article |
| id | doaj.art-2829f22313a040bca771f638cacea269 |
| institution | Directory Open Access Journal |
| issn | 2046-1402 |
| language | English |
| last_indexed | 2024-04-13T10:24:51Z |
| publishDate | 2019-11-01 |
| publisher | F1000 Research Ltd |
| record_format | Article |
| series | F1000Research |
| spelling | doaj.art-2829f22313a040bca771f638cacea2692022-12-22T02:50:21ZengF1000 Research LtdF1000Research2046-14022019-11-01810.12688/f1000research.18963.223232Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations]Gurprit Sekhon0Ranvir Singh1Department cum National Center for Human Genome Studies and Research, Panjab University, Chandigarh, 160014, IndiaDepartment cum National Center for Human Genome Studies and Research, Panjab University, Chandigarh, 160014, IndiaBackground: Human aldose reductase (hAR) is the first and rate-limiting enzyme of the polyol pathway. For the development of secondary complications of diabetes in chronic hyperglycemic conditions, one of the critical factors is the increased flux of glucose through the polyol pathway. Due to this clinical implication, hAR attracted considerable attention from the drug discovery perspective. In spite of extensive characterization in the context of biochemical and structural aspects, we know very little about the unfolding behavior of hAR. This study reports equilibrium unfolding studies of hAR. Methods: We carried out thermal denaturation and chemical-induced equilibrium unfolding studies of hAR monitored by circular dichroism and fluorescence spectroscopy. Results: Thermal denaturation studies presented a classical picture of two-state unfolding from native to the denatured state. The data was used to derive thermodynamic parameters and study the thermostability of hAR. Chemical induced equilibrium unfolding studies led us to discover an intermediate state, which gets populated at 3.5-4.0 M and 0.7-2.0 M of urea and GuHCl, respectively. Thermodynamic parameters derived from chemical-induced unfolding are in agreement with those obtained from thermal denaturation of hAR. Conclusion: This study revealed that aldose reductase unfolds from native to the unfolded state via an intermediate. Assessment of the thermodynamic stability of native, intermediate, and unfolded states shows that significant energy barriers separate these states, which ensures the cooperativity of unfolding. As hAR functions in cells that are under osmotic and oxidative stress, these in vitro findings may have implications for its native conformation under the physiological state.https://f1000research.com/articles/8-564/v2 |
| spellingShingle | Gurprit Sekhon Ranvir Singh Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations] F1000Research |
| title | Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations] |
| title_full | Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations] |
| title_fullStr | Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations] |
| title_full_unstemmed | Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations] |
| title_short | Human aldose reductase unfolds through an intermediate [version 2; peer review: 1 approved, 2 approved with reservations] |
| title_sort | human aldose reductase unfolds through an intermediate version 2 peer review 1 approved 2 approved with reservations |
| url | https://f1000research.com/articles/8-564/v2 |
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