Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study

It has been a long history that urea and guanidinium chloride (GdmCl) are used as agents for denaturing proteins. The underlying mechanism has been extensively studied in the past several decades. However, the question regarding why GdmCl is much stronger than urea has seldom been touched. Here, thr...

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Main Authors: Li, Weifeng, Mu, Yuguang
Other Authors: School of Biological Sciences
Format: Article
Language:English
Published: 2013
Online Access:https://hdl.handle.net/10356/97361
http://hdl.handle.net/10220/10744
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-973612020-03-07T12:18:19Z Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study Li, Weifeng Mu, Yuguang School of Biological Sciences School of Physical and Mathematical Sciences It has been a long history that urea and guanidinium chloride (GdmCl) are used as agents for denaturing proteins. The underlying mechanism has been extensively studied in the past several decades. However, the question regarding why GdmCl is much stronger than urea has seldom been touched. Here, through molecular dynamics simulations, we show that a 4 M GdmCl solution is more able than 7 M urea solution to dissociate both hydrophobic and charged nano-particles (NP). Both urea and GdmCl affect the NPs' aggregation through direct binding to the NP surface. The advantages of GdmCl originate from the net charge of bound guanidinium ions which can generate a local positively charged environment around hydrophobic and negatively charged NPs. This effective coating can introduce Coulombic repulsion between all the NPs. Urea shows certain ability to dissociate hydrophobic NPs. However, in the case of charged NPs, urea molecules located between two opposite-charged NPs will form ordered hydrogen bonds, acting like “glue” which prevents separation of the NPs. Although urea can form hydrogen bonds with either hydrophilic amino acids or the protein backbone, which are believed to contribute to protein denaturation, our findings strongly suggest that this property does not always contribute positively to urea's denaturation power. 2013-06-27T01:21:29Z 2019-12-06T19:41:52Z 2013-06-27T01:21:29Z 2019-12-06T19:41:52Z 2012 2012 Journal Article Li, W., & Mu, Y. (2012). Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions: A molecular dynamics study. Nanoscale, 4(4), 1154-1159. 2040-3364 https://hdl.handle.net/10356/97361 http://hdl.handle.net/10220/10744 10.1039/c1nr11108f en Nanoscale © 2012 The Royal Society of Chemistry.
institution Nanyang Technological University
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description It has been a long history that urea and guanidinium chloride (GdmCl) are used as agents for denaturing proteins. The underlying mechanism has been extensively studied in the past several decades. However, the question regarding why GdmCl is much stronger than urea has seldom been touched. Here, through molecular dynamics simulations, we show that a 4 M GdmCl solution is more able than 7 M urea solution to dissociate both hydrophobic and charged nano-particles (NP). Both urea and GdmCl affect the NPs' aggregation through direct binding to the NP surface. The advantages of GdmCl originate from the net charge of bound guanidinium ions which can generate a local positively charged environment around hydrophobic and negatively charged NPs. This effective coating can introduce Coulombic repulsion between all the NPs. Urea shows certain ability to dissociate hydrophobic NPs. However, in the case of charged NPs, urea molecules located between two opposite-charged NPs will form ordered hydrogen bonds, acting like “glue” which prevents separation of the NPs. Although urea can form hydrogen bonds with either hydrophilic amino acids or the protein backbone, which are believed to contribute to protein denaturation, our findings strongly suggest that this property does not always contribute positively to urea's denaturation power.
author2 School of Biological Sciences
author_facet School of Biological Sciences
Li, Weifeng
Mu, Yuguang
format Article
author Li, Weifeng
Mu, Yuguang
spellingShingle Li, Weifeng
Mu, Yuguang
Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
author_sort Li, Weifeng
title Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
title_short Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
title_full Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
title_fullStr Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
title_full_unstemmed Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
title_sort dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions : a molecular dynamics study
publishDate 2013
url https://hdl.handle.net/10356/97361
http://hdl.handle.net/10220/10744
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