dc.contributor.author
Sahoo, Anil Kumar
dc.contributor.author
Schreiber, Frank
dc.contributor.author
Netz, Roland R.
dc.contributor.author
Maiti, Prabal K.
dc.date.accessioned
2023-03-09T12:45:26Z
dc.date.available
2023-03-09T12:45:26Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/38095
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-37808
dc.description.abstract
Recent experiments have reported lower critical solution temperature (LCST) phase behavior of aqueous solutions of proteins induced by multivalent ions, where the solution phase separates upon heating. This phenomenon is linked to complex hydration effects that result in a net entropy gain upon phase separation. To decipher the underlying molecular mechanism, we use all-atom molecular dynamics simulations along with the two-phase thermodynamic method for entropy calculation. Based on simulations of a single BSA protein in various salt solutions (NaCl, CaCl2, MgCl2, and YCl3) at temperatures (T) ranging 283–323 K, we find that the cation–protein binding affinity increases with T, reflecting its thermodynamic driving force to be entropic in origin. We show that in the cation binding process, many tightly bound water molecules from the solvation shells of a cation and the protein are released to the bulk, resulting in entropy gain. To rationalize the LCST behavior, we calculate the ζ-potential that shows charge inversion of the protein for solutions containing multivalent ions. The ζ-potential increases with T. Performing simulations of two BSA proteins, we demonstrate that the protein–protein binding is mediated by multiple cation bridges and involves similar dehydration effects that cause a large entropy gain which more than compensates for rotational and translational entropy losses of the proteins. Thus, the LCST behavior is entropy-driven, but the associated solvation effects are markedly different from hydrophobic hydration. Our findings have direct implications for tuning the phase behavior of biological and soft-matter systems, e.g., protein condensation and crystallization.
en
dc.format.extent
10 Seiten
dc.rights.uri
http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen
dc.subject
lower critical solution temperature
en
dc.subject
protein solutions
en
dc.subject
phase behavior
en
dc.subject
biological and soft-matter systems
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik::530 Physik
dc.title
Role of entropy in determining the phase behavior of protein solutions induced by multivalent ions
dc.type
Wissenschaftlicher Artikel
dc.identifier.sepid
91846
dcterms.bibliographicCitation.doi
10.1039/D1SM00730K
dcterms.bibliographicCitation.journaltitle
Soft Matter
dcterms.bibliographicCitation.number
3
dcterms.bibliographicCitation.originalpublishername
RSC Publ.
dcterms.bibliographicCitation.originalpublisherplace
Cambridge
dcterms.bibliographicCitation.pagestart
592
dcterms.bibliographicCitation.pageend
601
dcterms.bibliographicCitation.volume
18 (2022)
dcterms.bibliographicCitation.url
http://xlink.rsc.org/?DOI=D1SM00730K
refubium.affiliation
Physik
refubium.affiliation.other
Institut für Theoretische Physik
refubium.note.author
Artikel in Allianz- und Nationallizenzen
de
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.issn
1744-683X
dcterms.isPartOf.issn
1744-6848