Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Macromolecular hydration compared with preferential hydration and their role on macromolecule-osmolyte coupled diffusionwz
 

Summary: Macromolecular hydration compared with preferential hydration
and their role on macromolecule-osmolyte coupled diffusionwz
Huixiang Zhangab
and Onofrio Annunziata*a
Received 22nd May 2009, Accepted 30th June 2009
First published as an Advance Article on the web 31st July 2009
DOI: 10.1039/b910152g
Hydration and preferential hydration of macromolecules are two distinct properties of their
multicomponent aqueous solutions. We have experimentally investigated ternary diffusion in a
macromolecule­osmolyte­water system in order to characterize and compare these two
independent quantities and to experimentally establish their role on the phenomenon
of coupled diffusion. Specifically, we report the four diffusion coefficients for the
poly(ethylene glycol)­di(ethylene glycol)­water system at 25 1C using Rayleigh interferometry.
In this work, the molecular weight of poly(ethylene glycol) (PEG) is 200-fold higher than that
of di(ethylene glycol) (DEG). This ratio is comparable to that between proteins and low
molecular-weight osmolytes. This system has been selected because both solutes are neutral
hydrated species with similar chemical properties and very different size. Hence, the observed
behavior of coupled diffusion can be directly related to solute hydration and size ratio and is not
complicated by other factors such as ionic interactions usually encountered in protein systems.
Using our multicomponent diffusion coefficients, we have found that PEG hydration is slightly

  

Source: Annunziata, Onofrio - Department of Chemistry, Texas Christian University

 

Collections: Chemistry