The effect of monovalent ions on polyphosphate binding to Escherichia coli exopolyphosphatase.
The thermodynamic driving force for the interaction of Escherichia coli exopolyphosphatase (PPX) with polyphosphate was investigated by varying salt choice and concentration. This interaction was found to be cation concentration independent but weakly dependent on the concentration of certain anions. Both of these traits are very uncommon for nonspecific protein-polyelectrolyte interactions. Interpretation of these results based on theory indicated that binding was not entropy driven due to release of polyelectrolyte-condensed counterions, as is the case for nearly all protein-polyelectrolyte interactions. The thermodynamics of the PPX-polyphosphate interaction showed similarity only to the interaction of polynucleotides with single stranded binding proteins.
Bolesch
D G
DG
Department of Chemical Engineering, University of California, Berkeley, California 94720-1462, USA. Doug_Bolesch@cc.chiron.com
Keasling
J D
JD
D017766:Acid Anhydride Hydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D002412:Cations / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019277:Entropy; D004926:Escherichia coli / Q000201:enzymology*; D005459:Fluorides / Q000494:pharmacology; D011122:Polyphosphates / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D017680:Potassium Compounds / Q000494:pharmacology; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013816:Thermodynamics
D002412:Cations; D011122:Polyphosphates; D017680:Potassium Compounds; D011189:Potassium Chloride; C033320:potassium fluoride; D017766:Acid Anhydride Hydrolases; C020137:exopolyphosphatase; D005459:Fluorides