Related Experiment Video
Updated: May 16, 2026

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
Published on: April 2, 2015
Determination of electrokinetic and hydrodynamic parameters of proteins by modeling their electrophoretic mobilities
Julio A Deiber1, María V Piaggio, Marta B Peirotti
1Instituto de Desarrollo Tecnológico para la Industria Química (INTEC), Universidad Nacional del Litoral (UNL), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina. treoflu@santafe-conicet.gov.ar
Abstract:
This work explores the possibility of using the electrically charged "spherical soft particle" (SSP) to model the electrophoretic mobility of proteins in the low charge regime. The general framework concerning the electrophoretic mobility of the SSP already presented in the literature is analyzed and discussed here in particular for polyampholyte-polypeptide chains. In this regard, this theory is applied to BSA for different protocol pH values. The physicochemical conditions required to model proteins as SSP from their experimentally determined electrophoretic mobilities are established. In particular, the protein charge regulation phenomenon and the SSP particle core are included to study BSA having isoelectric point pI ≈ 5.71, within a wide range of bulk pH values. The results of this case study are compared with previous ones concerning the spherical porous particle and the spherical hard particle with occluded water. A discussion of chain conformations in the SSP polyampholyte layer is presented through estimations of the packing and friction fractal dimensions.
Related Concept Videos
Electrophoresis: Overview
There...
Two-dimensional Gel Electrophoresis
The first dimension separation uses the isoelectric focusing or IEF technique performed on immobilized pH gradient (IPG) strips that separate proteins according to their isoelectric points.
Biological samples, such as cells...
Capillary Electrophoresis: Applications
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...
SDS-PAGE
A variation of gel electrophoresis, termed polyacrylamide gel electrophoresis (PAGE), is commonly used for separating proteins according to their molecular size by passing them through a polyacrylamide gel. Because of the varying charges associated with amino acid side chains, PAGE can be used to separate intact proteins...
Protein Diffusion in the Membrane
Protein Dynamics in Living Cells
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...

