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About thiol derivatization and resolution of basic proteins in two-dimensional electrophoresis

Sylvie Luche·Hélène Diemer·Chistophe Tastet·Mireille Chevallet·Alain Van Dorsselaer·Emmanuelle Leize-Wagner·Thierry Rabilloud
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Abstract

The influence of thiol blocking on the resolution of basic proteins by two-dimensional electrophoresis was investigated. Cysteine blocking greatly increased resolution and decreased streaking, especially in the basic region of the gels. Two strategies for cysteine blocking were found to be efficient: classical alkylation with maleimide derivatives and mixed disulfide exchange with an excess of a low molecular weight disulfide. The effect on resolution was significant enough to allow correct resolution of basic proteins with in-gel rehydration on wide gradients (e.g. 3-10 and 4-12), but anodic cup-loading was still required for basic gradients (e.g. 6-12 or 8-12). These results demonstrate that thiol-related problems are not solely responsible for streaking of basic proteins on two-dimensional gels.

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Sylvie Luche, Hélène Diemer, Chistophe Tastet, Mireille Chevallet, Alain Van Dorsselaer, Emmanuelle Leize-Wagner, Thierry Rabilloud. 2006-11-24. About thiol derivatization and resolution of basic proteins in two-dimensional electrophoresis. https://doi.org/10.1002/pmic.200300589

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