Molecular crowding effects of linear polymers in protein solutions
Data(s) |
01/01/2006
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Resumo |
Measurement of protein-polymer second virial coefficients (B-AP) by sedimentation equilibrium studies of carbonic anhydrase and cytochrome c in the presence of dextrans (T10-T80) has revealed an inverse dependence of B-AP upon dextran molecular mass that conforms well with the behaviour predicted for the excluded-volume interaction between a spherical protein solute A and a random-flight representation of the polymeric cosolute P. That model of the protein-polymer interaction is also shown to provide a reasonable description of published gel chromatographic and equilibrium dialysis data on the effect of polymer molecular mass on BAP for human serum albumin in the presence of polyethylene glycols, a contrary finding from analysis of albumin solubility measurements being rejected on theoretical grounds. Inverse dependence upon polymer chainlength is also the predicted excluded-volume effect on the strength of several types of macromolecular equilibria-protein isomerization, protein dimerization, and 1 : 1 complex formation between dissimilar protein reactants. It is therefore concluded that published experimental observations of the reverse dependence, preferential reaction enhancement within DNA replication complexes by larger polyethylene glycols, must reflect the consequences of cosolute chemical interactions that outweigh those of thermodynamic nonideality arising from excluded-volume effects. (c) 2005 Elsevier B.V. All rights reserved. |
Identificador | |
Idioma(s) |
eng |
Publicador |
Elsevier Science |
Palavras-Chave | #Protein-polymer Virial Coefficients #Thermodynamic Nonideality #Polymer Molecular-crowding Effects #Dextrans #Polyethylene Glycols #Biochemistry & Molecular Biology #Biophysics #Chemistry, Physical #Size-exclusion Chromatography #Muscle Pyruvate-kinase #Polyethylene-glycol #Isomerization Equilibrium #Sedimentation Equilibrium #Macromolecular Solutions #Replication Complex #Self-association #Aqueous-solution #C1 #270100 Biochemistry and Cell Biology #780105 Biological sciences |
Tipo |
Journal Article |