Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling

Constitutive phosphorylation activity by receptor tyrosine kinases due to activating mutations have been linked to human malignancies. Substitution mutation of tyrosine 849 to serine residue led to the constitutive phosphorylation of platelet-derived growth factor receptor alpha (PDGFRa) as found in...

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Main Author: Hussin, Nurulfarhana
Format: Thesis
Language:English
Published: 2015
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Online Access:http://eprints.utm.my/id/eprint/54058/25/NurulfarhanaHussinMFBME2015.pdf
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spelling my-utm-ep.540582020-10-15T03:15:14Z Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling 2015-02 Hussin, Nurulfarhana R Medicine (General) Constitutive phosphorylation activity by receptor tyrosine kinases due to activating mutations have been linked to human malignancies. Substitution mutation of tyrosine 849 to serine residue led to the constitutive phosphorylation of platelet-derived growth factor receptor alpha (PDGFRa) as found in hypereosinophilic syndrome sample. An in silico study was conducted to identify whether PDGFRa catalytic domain can adopt an inactive conformation. The activating mutation Y849S was investigated to elucidate its role in destabilizing the inactive state of wild type PDGFRa catalytic domain. Three dimensional structure of PDGFRa catalytic domain in inactive conformation was modelled and refined with MD simulations using GROMOS96 force field with 53a6 parameter in GROMACS version 4.6.3. The model consists of juxtamembrane (JM) region and kinase domain. Presence of conserved tyrosine and tryptophan residues in JM region suggested its stabilizing role in inactive structure. Analysis of MD trajectories indicated that mutation Y849S at the C-terminal lobe had caused the loss of intramolecular hydrogen bondings which contributed to the increase of JM region fluctuations in the N-terminal lobe, higher hydrophilicity of activation loop (A-loop) that might loosen its packed conformation, and more solvent-exposed of JM region as a result of its reduced hydrophobicity. The shorter, non-aromatic side chain of serine residue at the position 849 is incapable to preserve the hydrogen bond network played by tyrosine residue in the wild type model. In conclusion, it is suggested, at least based on the model from this study that Y849 might play as stabilizing role in inactive conformation of PDGFRa catalytic domain by linking the inter-lobe interactions of A-loop and JM regions. Substitution of serine at the same position perturbs the interactions thus destabilize the inactive conformational state of the model. 2015-02 Thesis http://eprints.utm.my/id/eprint/54058/ http://eprints.utm.my/id/eprint/54058/25/NurulfarhanaHussinMFBME2015.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:86247 masters Universiti Teknologi Malaysia, Faculty of Biosciences and Medical Engineering Faculty of Biosciences and Medical Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic R Medicine (General)
spellingShingle R Medicine (General)
Hussin, Nurulfarhana
Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
description Constitutive phosphorylation activity by receptor tyrosine kinases due to activating mutations have been linked to human malignancies. Substitution mutation of tyrosine 849 to serine residue led to the constitutive phosphorylation of platelet-derived growth factor receptor alpha (PDGFRa) as found in hypereosinophilic syndrome sample. An in silico study was conducted to identify whether PDGFRa catalytic domain can adopt an inactive conformation. The activating mutation Y849S was investigated to elucidate its role in destabilizing the inactive state of wild type PDGFRa catalytic domain. Three dimensional structure of PDGFRa catalytic domain in inactive conformation was modelled and refined with MD simulations using GROMOS96 force field with 53a6 parameter in GROMACS version 4.6.3. The model consists of juxtamembrane (JM) region and kinase domain. Presence of conserved tyrosine and tryptophan residues in JM region suggested its stabilizing role in inactive structure. Analysis of MD trajectories indicated that mutation Y849S at the C-terminal lobe had caused the loss of intramolecular hydrogen bondings which contributed to the increase of JM region fluctuations in the N-terminal lobe, higher hydrophilicity of activation loop (A-loop) that might loosen its packed conformation, and more solvent-exposed of JM region as a result of its reduced hydrophobicity. The shorter, non-aromatic side chain of serine residue at the position 849 is incapable to preserve the hydrogen bond network played by tyrosine residue in the wild type model. In conclusion, it is suggested, at least based on the model from this study that Y849 might play as stabilizing role in inactive conformation of PDGFRa catalytic domain by linking the inter-lobe interactions of A-loop and JM regions. Substitution of serine at the same position perturbs the interactions thus destabilize the inactive conformational state of the model.
format Thesis
qualification_level Master's degree
author Hussin, Nurulfarhana
author_facet Hussin, Nurulfarhana
author_sort Hussin, Nurulfarhana
title Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
title_short Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
title_full Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
title_fullStr Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
title_full_unstemmed Structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
title_sort structural analysis of platelet-derived growth factor receptor alpha by protein homology modeling
granting_institution Universiti Teknologi Malaysia, Faculty of Biosciences and Medical Engineering
granting_department Faculty of Biosciences and Medical Engineering
publishDate 2015
url http://eprints.utm.my/id/eprint/54058/25/NurulfarhanaHussinMFBME2015.pdf
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