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Temperature-induced phase partitioning of peptides in water solutions of ethylene oxide and propylene oxide random copolymers

Johansson, Hans-Olof LU ; Karlström, Gunnar LU and Tjerneld, Folke LU (1997) In Biochimica et Biophysica Acta. General Subjects 1335(3). p.315-325
Abstract
A thermoseparating random copolymer (Ucon 50-HB-5100) composed of (50%) ethylene oxide and (50%) propylene oxide has been used to form an aqueous two-phase system by heating the polymer-water solution above the cloud point of the copolymer. In the formed two-phase system a water rich top phase is in equilibrium with an aqueous polymer rich bottom phase. The partitioning of amino acids and peptides in this aqueous two-phase system has been studied. Hydrophobic peptides (containing aromatic amino acids) were strongly partitioned to the polymer rich phase, while hydrophilic peptides were enriched in the water rich phase. The effect of temperature on the partitioning was investigated and a decreased partitioning to the polymer rich phase was... (More)
A thermoseparating random copolymer (Ucon 50-HB-5100) composed of (50%) ethylene oxide and (50%) propylene oxide has been used to form an aqueous two-phase system by heating the polymer-water solution above the cloud point of the copolymer. In the formed two-phase system a water rich top phase is in equilibrium with an aqueous polymer rich bottom phase. The partitioning of amino acids and peptides in this aqueous two-phase system has been studied. Hydrophobic peptides (containing aromatic amino acids) were strongly partitioned to the polymer rich phase, while hydrophilic peptides were enriched in the water rich phase. The effect of temperature on the partitioning was investigated and a decreased partitioning to the polymer rich phase was obtained upon temperature increase. The effect of two salts (NaClO4 and Na2SO4) on the partitioning of a positively charged polypeptide, poly(Lys, Trp), was very strong. With NaClO4 the polypeptide was quantitatively partitioned to the polymer rich phase while with Na2SO4 the polypeptide was partitioned to the water rich phase. Model calculations based on a modified Flory-Huggins theory have been performed to better understand the experimental behavior. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Polymer, Phase separation, Peptide, Aqueous two-phase system, Temperature-induced phase separation
in
Biochimica et Biophysica Acta. General Subjects
volume
1335
issue
3
pages
315 - 325
publisher
Elsevier
external identifiers
  • scopus:0030971323
ISSN
0304-4165
DOI
10.1016/S0304-4165(96)00150-X
language
English
LU publication?
yes
id
a2337dff-409d-45f0-8362-13147373239c (old id 126181)
date added to LUP
2007-07-05 16:05:44
date last changed
2017-04-09 04:13:14
@article{a2337dff-409d-45f0-8362-13147373239c,
  abstract     = {A thermoseparating random copolymer (Ucon 50-HB-5100) composed of (50%) ethylene oxide and (50%) propylene oxide has been used to form an aqueous two-phase system by heating the polymer-water solution above the cloud point of the copolymer. In the formed two-phase system a water rich top phase is in equilibrium with an aqueous polymer rich bottom phase. The partitioning of amino acids and peptides in this aqueous two-phase system has been studied. Hydrophobic peptides (containing aromatic amino acids) were strongly partitioned to the polymer rich phase, while hydrophilic peptides were enriched in the water rich phase. The effect of temperature on the partitioning was investigated and a decreased partitioning to the polymer rich phase was obtained upon temperature increase. The effect of two salts (NaClO4 and Na2SO4) on the partitioning of a positively charged polypeptide, poly(Lys, Trp), was very strong. With NaClO4 the polypeptide was quantitatively partitioned to the polymer rich phase while with Na2SO4 the polypeptide was partitioned to the water rich phase. Model calculations based on a modified Flory-Huggins theory have been performed to better understand the experimental behavior.},
  author       = {Johansson, Hans-Olof and Karlström, Gunnar and Tjerneld, Folke},
  issn         = {0304-4165},
  keyword      = {Polymer,Phase separation,Peptide,Aqueous two-phase system,Temperature-induced phase separation},
  language     = {eng},
  number       = {3},
  pages        = {315--325},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta. General Subjects},
  title        = {Temperature-induced phase partitioning of peptides in water solutions of ethylene oxide and propylene oxide random copolymers},
  url          = {http://dx.doi.org/10.1016/S0304-4165(96)00150-X},
  volume       = {1335},
  year         = {1997},
}