The allosteric modulation of thyroxine-binding globulin affinity is entropy driven
Background Thyroxine-binding globulin (TBG) is a non-inhibitory member of the serpin family of proteins whose main structural element is the reactive center loop (RCL), that, upon cleavage by proteases, is inserted into the protein core adopting a β-strand conformation (stressed to relaxed transitio...
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2013
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03044165_v1830_n6_p3570_Petruk http://hdl.handle.net/20.500.12110/paper_03044165_v1830_n6_p3570_Petruk |
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paper:paper_03044165_v1830_n6_p3570_Petruk2023-06-08T15:29:52Z The allosteric modulation of thyroxine-binding globulin affinity is entropy driven Allostery Conformational entropy Generalized Born surface analysis Molecular dynamics Serpin family Thyroxine-binding globulin proteinase thyroxine thyroxine binding globulin allosterism article binding affinity binding site complex formation conformational transition controlled study entropy enzyme activity hydrogen bond molecular dynamics priority journal protein binding protein conformation protein interaction protein localization protein secondary structure protein stability protein structure reaction time reactive center loop structure analysis Allosteric Regulation Binding Sites Crystallography, X-Ray Entropy Humans Protein Structure, Secondary Thyroxine Thyroxine-Binding Globulin Background Thyroxine-binding globulin (TBG) is a non-inhibitory member of the serpin family of proteins whose main structural element is the reactive center loop (RCL), that, upon cleavage by proteases, is inserted into the protein core adopting a β-strand conformation (stressed to relaxed transition, S-to-R). After S-to-R transition thyroxine (T4) affinity decreases. However, crystallographic studies in the presence or absence of the hormone in different states are unable to show significant differences in the structure and interactions of the binding site. Experimental results also suggest the existence of several S states (differing in the number of inserted RCL residues), associated with a differential affinity. Methods To shed light into the molecular basis that regulates T4 affinity according to the degree of RCL insertion in TBG, we performed extended molecular dynamics simulations combined with several thermodynamic analysis of the T4 binding to TBG in three different S states, and in the R state. Results Our results show that, despite T4 binding in the protein by similar interactions in all states, a good correlation between the degree of RCL insertion and the binding affinity, driven by a change in TBG conformational entropy, was observed. Conclusion TBG allosteric regulation is entropy driven. The presence of multiple S states may allow more efficient T4 release due to protease activity. General significance The presented results are clear examples of how computer simulation methods can reveal the thermodynamic basis of allosteric effects, and provide a general framework for understanding serpin allosteric affinity regulation. © 2013 Elsevier B.V. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03044165_v1830_n6_p3570_Petruk http://hdl.handle.net/20.500.12110/paper_03044165_v1830_n6_p3570_Petruk |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Allostery Conformational entropy Generalized Born surface analysis Molecular dynamics Serpin family Thyroxine-binding globulin proteinase thyroxine thyroxine binding globulin allosterism article binding affinity binding site complex formation conformational transition controlled study entropy enzyme activity hydrogen bond molecular dynamics priority journal protein binding protein conformation protein interaction protein localization protein secondary structure protein stability protein structure reaction time reactive center loop structure analysis Allosteric Regulation Binding Sites Crystallography, X-Ray Entropy Humans Protein Structure, Secondary Thyroxine Thyroxine-Binding Globulin |
| spellingShingle |
Allostery Conformational entropy Generalized Born surface analysis Molecular dynamics Serpin family Thyroxine-binding globulin proteinase thyroxine thyroxine binding globulin allosterism article binding affinity binding site complex formation conformational transition controlled study entropy enzyme activity hydrogen bond molecular dynamics priority journal protein binding protein conformation protein interaction protein localization protein secondary structure protein stability protein structure reaction time reactive center loop structure analysis Allosteric Regulation Binding Sites Crystallography, X-Ray Entropy Humans Protein Structure, Secondary Thyroxine Thyroxine-Binding Globulin The allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| topic_facet |
Allostery Conformational entropy Generalized Born surface analysis Molecular dynamics Serpin family Thyroxine-binding globulin proteinase thyroxine thyroxine binding globulin allosterism article binding affinity binding site complex formation conformational transition controlled study entropy enzyme activity hydrogen bond molecular dynamics priority journal protein binding protein conformation protein interaction protein localization protein secondary structure protein stability protein structure reaction time reactive center loop structure analysis Allosteric Regulation Binding Sites Crystallography, X-Ray Entropy Humans Protein Structure, Secondary Thyroxine Thyroxine-Binding Globulin |
| description |
Background Thyroxine-binding globulin (TBG) is a non-inhibitory member of the serpin family of proteins whose main structural element is the reactive center loop (RCL), that, upon cleavage by proteases, is inserted into the protein core adopting a β-strand conformation (stressed to relaxed transition, S-to-R). After S-to-R transition thyroxine (T4) affinity decreases. However, crystallographic studies in the presence or absence of the hormone in different states are unable to show significant differences in the structure and interactions of the binding site. Experimental results also suggest the existence of several S states (differing in the number of inserted RCL residues), associated with a differential affinity. Methods To shed light into the molecular basis that regulates T4 affinity according to the degree of RCL insertion in TBG, we performed extended molecular dynamics simulations combined with several thermodynamic analysis of the T4 binding to TBG in three different S states, and in the R state. Results Our results show that, despite T4 binding in the protein by similar interactions in all states, a good correlation between the degree of RCL insertion and the binding affinity, driven by a change in TBG conformational entropy, was observed. Conclusion TBG allosteric regulation is entropy driven. The presence of multiple S states may allow more efficient T4 release due to protease activity. General significance The presented results are clear examples of how computer simulation methods can reveal the thermodynamic basis of allosteric effects, and provide a general framework for understanding serpin allosteric affinity regulation. © 2013 Elsevier B.V. |
| title |
The allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| title_short |
The allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| title_full |
The allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| title_fullStr |
The allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| title_full_unstemmed |
The allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| title_sort |
allosteric modulation of thyroxine-binding globulin affinity is entropy driven |
| publishDate |
2013 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03044165_v1830_n6_p3570_Petruk http://hdl.handle.net/20.500.12110/paper_03044165_v1830_n6_p3570_Petruk |
| _version_ |
1768545691323334656 |