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Effect of background electrolyte on the estimation of protein hydrodynamic radius and net charge through capillary zone electrophoresis
Author(s) -
Piaggio Maria V.,
Peirotti Marta B.,
Deiber Julio A.
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200500161
Subject(s) - electrophoresis , radius , capillary electrophoresis , electrolyte , charge (physics) , chemistry , carbonic anhydrase ii , hydrodynamic radius , charge density , chromatography , carbonic anhydrase , physics , biochemistry , computer science , enzyme , aqueous solution , computer security , electrode , quantum mechanics , micelle
Abstract Two physicochemical models are proposed for the estimation of both hydrodynamic radius and net charge of a protein when the capillary zone electrophoretic mobility at a given protocol, the set of p K of charged amino acids, and basic data from Protein Data Bank are available. These models also provide a rationale to interpret appropriately the effects of solvent properties on protein hydrodynamic radius and net charge. To illustrate the numerical predictions of these models, experimental data of electrophoretic mobility available in the literature for well‐defined protocols are used. Five proteins are considered: lysozyme, staphylococcal nuclease, human carbonic anhydrase, bovine carbonic anhydrase, and human serum albumin. Numerical predictions of protein net charges through these models compare well with the results reported in the literature, including those found asymptotically through protein charge ladder techniques. Model calculations indicate that the hydrodynamic radius is sensitive to changes of the protein net charge and hence it cannot be assumed constant in general. Also, several limitations associated with models for estimating protein net charge and hydrodynamic radius from protein structure, amino acid sequence, and experimental electrophoretic mobility are provided and discussed. These conclusions also show clear requirements for further research.