Isoelectric immobilized

Righetti, P. G., Isoelectric focusing of proteins in conventional and immobilized pH gradients, in Protein Structure A Practical Approach, Creighton, T. E., Ed., IRL Press, New York, 1989, 23. 

Ek, K., Bjellqvist, B., Righetti, R G. (1983). preparative isoelectric-focusing in immobilized pH Gradients. 1. General principles and methodology. J. Biochem. Bioph. Meth. 8(2), 135-155. 

Essader, A.S., Cargile, B.J., Bundy, J.L., Stephenson, J.L., Jr. (2005). A comparison of immobilized pH gradient isoelectric focusing and strong-cation-exchange chromatography as a first dimension in shotgun proteomics. Proteomics 5, 24—34. 

Norbeck J et al. Two-dimensional electrophoretic separation of yeast proteins using a non-linear wide range (pH 3-10) immobilized pH gradient in the first dimension reproducibility and evidence for isoelectric focusing of alkaline (pi >7) proteins. Yeast 1997 13 1519-1534. 

The immobilization procedure performed in two stages allows one to exclude the detrimental effect of acid on the entrapped proteins [44,71,86]. It was demonstrated [87] by the example of a set of oxidases that their activity was retained if the entrapment was carried out at a pH as close to their isoelectric point (pi) as possible. Because the pi value of most enzymes is in the neutral region, the two-stage procedure favors the retention of their functionality. Therefore, the pH shift to the optimal region provides a means of extending the sol-gel entrapment to a wide range of enzymes [45,71]. 

PI. Pirttila, T., Frey, H., Mattila, K., and Siden, L., Immobilized pH gradient isoelectric focusing of cerebrospinal fluid proteins. Electrophoresis 9, 582-588 (1988). 

Haase R, Menke-Mollers I, Oette (1988) Analysis of human apolipoproteins C by isoelectric focusing in immobilized pH gradients. Electrophoresis 9 569-575... 

Fig. 17.6. Isoelectric focusing diagrammatic view of isoelectric focusing (IEF) of a re-hydrated linear immobilized pH 3-10 gradient strip (Biorad, UK).

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