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PFG-NMR diffusometry: A tool for investigating the structure and dynamics of noncommercial purified pig gastric mucin in a wide range of concentrations

Lafitte, Géraldine LU ; Söderman, Olle LU ; Thuresson, Krister LU and Davies, Julia LU (2007) In Biopolymers 86(2). p.165-175
Abstract
For the first time, Pulsed Field Gradient-Nuclear Magnetic Resonance, a powerful noninvasive tool for studying the dynamics and structure of complex-gels, has been used to measure diffusion of probe molecules in aqueous solutions/gels of noncommercial purified pig gastric mucin (PGM), in a concentration range up to 5 wt%. Complementary data were obtained from rheology measurements. The combination of techniques revealed a strong pH dependency of the structure of the PGM samples while changes in concentration, ionic strength, and temperature appeared to induce less pronounced alterations. Viscosity was found to vary in a nonmonotonous way with pH, with the more viscous solutions found at intermediate pH. We propose that this finding is due... (More)
For the first time, Pulsed Field Gradient-Nuclear Magnetic Resonance, a powerful noninvasive tool for studying the dynamics and structure of complex-gels, has been used to measure diffusion of probe molecules in aqueous solutions/gels of noncommercial purified pig gastric mucin (PGM), in a concentration range up to 5 wt%. Complementary data were obtained from rheology measurements. The combination of techniques revealed a strong pH dependency of the structure of the PGM samples while changes in concentration, ionic strength, and temperature appeared to induce less pronounced alterations. Viscosity was found to vary in a nonmonotonous way with pH, with the more viscous solutions found at intermediate pH. We propose that this finding is due to a reduced charge density at lower pH, which is expected to continuously increase the relative importance of hydrophobic associations. The results suggest a loose network of expanded fully charged PGM molecules woth considerable mobility at neutral pH (pH 7.4). At intermediate pH (pH 4), a three-dimensional expanded network is favored. At pH 1, the charge density is low and microphase seperation occurs since hydrophobic associations prevail. This leads to the formation of clusters concentrated in PGM molecules seperated by regions depleted in PGM. The results obtained increase our knowledge about the gastric mucosal layer, which in vivo contains mucin in the same concentration range as that of the samples investigated here. (c) 2007 Wiley Periodicals, Inc. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
rheology, PEG, structure and dynamics, mucin gel, PFG-NMR diffusometry
in
Biopolymers
volume
86
issue
2
pages
165 - 175
publisher
John Wiley & Sons Inc.
external identifiers
  • wos:000246578500010
  • scopus:34249341374
  • pmid:17345632
ISSN
0006-3525
DOI
10.1002/bip.20717
language
English
LU publication?
yes
id
029fafc9-cfc2-4465-b84b-1eaacf14ac84 (old id 657580)
date added to LUP
2016-04-01 11:36:04
date last changed
2022-01-26 07:26:20
@article{029fafc9-cfc2-4465-b84b-1eaacf14ac84,
  abstract     = {{For the first time, Pulsed Field Gradient-Nuclear Magnetic Resonance, a powerful noninvasive tool for studying the dynamics and structure of complex-gels, has been used to measure diffusion of probe molecules in aqueous solutions/gels of noncommercial purified pig gastric mucin (PGM), in a concentration range up to 5 wt%. Complementary data were obtained from rheology measurements. The combination of techniques revealed a strong pH dependency of the structure of the PGM samples while changes in concentration, ionic strength, and temperature appeared to induce less pronounced alterations. Viscosity was found to vary in a nonmonotonous way with pH, with the more viscous solutions found at intermediate pH. We propose that this finding is due to a reduced charge density at lower pH, which is expected to continuously increase the relative importance of hydrophobic associations. The results suggest a loose network of expanded fully charged PGM molecules woth considerable mobility at neutral pH (pH 7.4). At intermediate pH (pH 4), a three-dimensional expanded network is favored. At pH 1, the charge density is low and microphase seperation occurs since hydrophobic associations prevail. This leads to the formation of clusters concentrated in PGM molecules seperated by regions depleted in PGM. The results obtained increase our knowledge about the gastric mucosal layer, which in vivo contains mucin in the same concentration range as that of the samples investigated here. (c) 2007 Wiley Periodicals, Inc.}},
  author       = {{Lafitte, Géraldine and Söderman, Olle and Thuresson, Krister and Davies, Julia}},
  issn         = {{0006-3525}},
  keywords     = {{rheology; PEG; structure and dynamics; mucin gel; PFG-NMR diffusometry}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{165--175}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Biopolymers}},
  title        = {{PFG-NMR diffusometry: A tool for investigating the structure and dynamics of noncommercial purified pig gastric mucin in a wide range of concentrations}},
  url          = {{http://dx.doi.org/10.1002/bip.20717}},
  doi          = {{10.1002/bip.20717}},
  volume       = {{86}},
  year         = {{2007}},
}