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LUND UNIVERSITY LIBRARIES

Probing the Intermolecular Interactions of Lactoferrin

Morin, Maxim LU (2013) KEMK07 20131
Department of Chemistry
Abstract (Swedish)
Populärvetenskaplig sammanfattning
Protein-protein växelverkan för det globulära proteinet laktoferrin har studerats vid låg elektrolythalt (5 mM) med hjälp av statisk ljusspridning och mätningar av andra virial koefficienten, B2 som innehåller information om protein-protein växelverkan. Växelverkan mellan proteinmolekyler är mycket komplex vilket beror på de ingående aminosyrornas egenskaper. Dessa proteininteraktioner är starkt beroende av lösningens pH och jonstyrka som påverkar proteinets laddning och även den sammanlagda växelverkan på ett inte självklart sätt. Från MC datorsimuleringar har man funnit att laktoferrin har en fläckvis attraktiv växelverkan och denna attraktion skall under vissa betingelser (pH nära PI samt låg... (More)
Populärvetenskaplig sammanfattning
Protein-protein växelverkan för det globulära proteinet laktoferrin har studerats vid låg elektrolythalt (5 mM) med hjälp av statisk ljusspridning och mätningar av andra virial koefficienten, B2 som innehåller information om protein-protein växelverkan. Växelverkan mellan proteinmolekyler är mycket komplex vilket beror på de ingående aminosyrornas egenskaper. Dessa proteininteraktioner är starkt beroende av lösningens pH och jonstyrka som påverkar proteinets laddning och även den sammanlagda växelverkan på ett inte självklart sätt. Från MC datorsimuleringar har man funnit att laktoferrin har en fläckvis attraktiv växelverkan och denna attraktion skall under vissa betingelser (pH nära PI samt låg jonstyrka) ge upphov till dimerbildning. Vi avser använda laktoferrin som modelsystem för fläckvis attraktion och i detta arbete har den andra virial koefficienten, B2, bestämts vid lågt pH och jonstyrka, vilket motsvarar repulsiv växelverkan. (Less)
Abstract
In this work the effect of pH and ionic strength on interactions for the globular protein lactoferrin has been studied using static and dynamic light scattering. The interactions were investigated in terms of the second virial coefficient, B2, and the collective diffusion coefficient, Dcoll, at different concentrations of electrolyte. The conditions investigated in this work will serve as a stable point-of-departure from which we will set out, in a controlled way, to explore the phase diagram with the aim to use lactoferrin as a model protein to investigate the role of patchy attractive interactions, i.e. charged groups and hydrophobic groups are unevenly distributed at the protein surface. The charged groups depend strongly on both pH and... (More)
In this work the effect of pH and ionic strength on interactions for the globular protein lactoferrin has been studied using static and dynamic light scattering. The interactions were investigated in terms of the second virial coefficient, B2, and the collective diffusion coefficient, Dcoll, at different concentrations of electrolyte. The conditions investigated in this work will serve as a stable point-of-departure from which we will set out, in a controlled way, to explore the phase diagram with the aim to use lactoferrin as a model protein to investigate the role of patchy attractive interactions, i.e. charged groups and hydrophobic groups are unevenly distributed at the protein surface. The charged groups depend strongly on both pH and ionic strength. The overall reproducibility and stability against time are crucial and shown here to be highly satisfactory. From determination of B2 the interactions are found to be, at the investigated pH and ionic strength, overall repulsive and in agreement with computer simulations and preliminary SAXS measurements. However, the collective diffusion coefficient appears to be, under the same conditions, not as repulsive which calls for further measurements and analysis. (Less)
Please use this url to cite or link to this publication:
author
Morin, Maxim LU
supervisor
organization
course
KEMK07 20131
year
type
M2 - Bachelor Degree
subject
keywords
Fysikalisk kemi, Physical Chemistry
language
English
id
4121643
date added to LUP
2013-10-30 11:02:03
date last changed
2013-10-30 11:02:03
@misc{4121643,
  abstract     = {In this work the effect of pH and ionic strength on interactions for the globular protein lactoferrin has been studied using static and dynamic light scattering. The interactions were investigated in terms of the second virial coefficient, B2, and the collective diffusion coefficient, Dcoll, at different concentrations of electrolyte. The conditions investigated in this work will serve as a stable point-of-departure from which we will set out, in a controlled way, to explore the phase diagram with the aim to use lactoferrin as a model protein to investigate the role of patchy attractive interactions, i.e. charged groups and hydrophobic groups are unevenly distributed at the protein surface. The charged groups depend strongly on both pH and ionic strength. The overall reproducibility and stability against time are crucial and shown here to be highly satisfactory. From determination of B2 the interactions are found to be, at the investigated pH and ionic strength, overall repulsive and in agreement with computer simulations and preliminary SAXS measurements. However, the collective diffusion coefficient appears to be, under the same conditions, not as repulsive which calls for further measurements and analysis.},
  author       = {Morin, Maxim},
  keyword      = {Fysikalisk kemi,Physical Chemistry},
  language     = {eng},
  note         = {Student Paper},
  title        = {Probing the Intermolecular Interactions of Lactoferrin},
  year         = {2013},
}