Protein focusing in a conductivity gradient.

R D Greenlee; C F Ivory

doi:10.1021/bp970113v

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PubMed · 9548784

Protein focusing in a conductivity gradient.

R D Greenlee·C F Ivory

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Abstract

Conductivity gradient focusing (CGF) is one member of a family of gradient focusing techniques, characterized by two opposing forces which produce a dynamic equilibrium and which are able to simultaneously separate and concentrate proteins. In CGF, the two counteracting forces result from a constant convective flow of buffer opposed by an electric field gradient. This gradient in the electric field is formed by gradually decreasing buffer conductivity, i.e., when a slow-moving, relatively high conductivity buffer is dialyzed against a low conductivity purge buffer. This paper presents the design of an analytical-scale CGF device and the results of several experiments with colored proteins, both in free solution and with the use of a 45 micron size-exclusion (SEC) packing to decrease dispersion. Experimental results with hemoglobin suggest that CGF may one day be capable of resolving proteins with small charge differences. A linear computer model of conductivity gradient focusing is derived, and some suggestions are made for further development of this new electrophoretic method.

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Buffers Chromatography Diffusion Electric Conductivity Electromagnetic Fields Isoelectric Focusing Linear Models Membranes, Artificial Proteins Journal Article

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R D Greenlee, C F Ivory. Protein focusing in a conductivity gradient.. https://doi.org/10.1021/bp970113v

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