Calcium binding and disulfide bonds regulate the stability of Secretagogin towards thermal and urea denaturation
(2016) In PLoS ONE 11(11).- Abstract
Secretagogin is a calcium-sensor protein with six EF-hands. It is widely expressed in neurons and neuro-endocrine cells of a broad range of vertebrates including mammals, fishes and amphibia. The protein plays a role in secretion and interacts with several vesicle-associated proteins. In this work, we have studied the contribution of calcium binding and disulfide-bond formation to the stability of the secretagogin structure towards thermal and urea denaturation. SDS-PAGE analysis of secretagogin in reducing and non-reducing conditions identified a tendency of the protein to form dimers in a redox-dependent manner. The denaturation of apo and Calcium-loaded secretagogin was studied by circular dichroism and fluorescence spectroscopy... (More)
Secretagogin is a calcium-sensor protein with six EF-hands. It is widely expressed in neurons and neuro-endocrine cells of a broad range of vertebrates including mammals, fishes and amphibia. The protein plays a role in secretion and interacts with several vesicle-associated proteins. In this work, we have studied the contribution of calcium binding and disulfide-bond formation to the stability of the secretagogin structure towards thermal and urea denaturation. SDS-PAGE analysis of secretagogin in reducing and non-reducing conditions identified a tendency of the protein to form dimers in a redox-dependent manner. The denaturation of apo and Calcium-loaded secretagogin was studied by circular dichroism and fluorescence spectroscopy under conditions favoring monomer or dimer or a 1:1 monomer: dimer ratio. This analysis reveals significantly higher stability towards urea denaturation of Calcium-loaded secretagogin compared to the apo protein. The secondary and tertiary structure of the Calcium-loaded form is not completely denatured in the presence of 10 M urea. Reduced and Calcium-loaded secretagogin is found to refold reversibly after heating to 95°C, while both oxidized and reduced apo secretagogin is irreversibly denatured at this temperature. Thus, calcium binding greatly stabilizes the structure of secretagogin towards chemical and heat denaturation.
(Less)
- author
- Sanagavarapu, Kalyani LU ; Weiffert, Tanja LU ; Mhurchú, Niamh Ní ; O'Connell, David and Linse, Sara LU
- organization
- publishing date
- 2016-11-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- PLoS ONE
- volume
- 11
- issue
- 11
- article number
- e0165709
- publisher
- Public Library of Science (PLoS)
- external identifiers
-
- scopus:84994051886
- pmid:27812162
- wos:000386910000050
- ISSN
- 1932-6203
- DOI
- 10.1371/journal.pone.0165709
- language
- English
- LU publication?
- yes
- id
- bc5d457d-1186-4929-92d6-1f082ebfb7a3
- date added to LUP
- 2016-11-21 09:44:04
- date last changed
- 2024-10-05 06:01:31
@article{bc5d457d-1186-4929-92d6-1f082ebfb7a3,
abstract = {{<p>Secretagogin is a calcium-sensor protein with six EF-hands. It is widely expressed in neurons and neuro-endocrine cells of a broad range of vertebrates including mammals, fishes and amphibia. The protein plays a role in secretion and interacts with several vesicle-associated proteins. In this work, we have studied the contribution of calcium binding and disulfide-bond formation to the stability of the secretagogin structure towards thermal and urea denaturation. SDS-PAGE analysis of secretagogin in reducing and non-reducing conditions identified a tendency of the protein to form dimers in a redox-dependent manner. The denaturation of apo and Calcium-loaded secretagogin was studied by circular dichroism and fluorescence spectroscopy under conditions favoring monomer or dimer or a 1:1 monomer: dimer ratio. This analysis reveals significantly higher stability towards urea denaturation of Calcium-loaded secretagogin compared to the apo protein. The secondary and tertiary structure of the Calcium-loaded form is not completely denatured in the presence of 10 M urea. Reduced and Calcium-loaded secretagogin is found to refold reversibly after heating to 95°C, while both oxidized and reduced apo secretagogin is irreversibly denatured at this temperature. Thus, calcium binding greatly stabilizes the structure of secretagogin towards chemical and heat denaturation.</p>}},
author = {{Sanagavarapu, Kalyani and Weiffert, Tanja and Mhurchú, Niamh Ní and O'Connell, David and Linse, Sara}},
issn = {{1932-6203}},
language = {{eng}},
month = {{11}},
number = {{11}},
publisher = {{Public Library of Science (PLoS)}},
series = {{PLoS ONE}},
title = {{Calcium binding and disulfide bonds regulate the stability of Secretagogin towards thermal and urea denaturation}},
url = {{http://dx.doi.org/10.1371/journal.pone.0165709}},
doi = {{10.1371/journal.pone.0165709}},
volume = {{11}},
year = {{2016}},
}