Coupling of PEG to Proteins by Activation with Tresyl Chloride. Applications in Immunoaffinity Cell Partitioning
Cell partitioning in aqueous two-phase systems formed by dextran and poly(ethylene glycol) (PEG) is a developing technique for cell fractionation using countercurrent distribution, which has been used to separate a wide range of cell types on the basis of surface properties such as charge, hydrophobicity and ligand binding [1,2]. Nevertheless, the method has lacked the specificity required for most biological separation problems. Recently, a dramatic increase in the selectivity of partitioning has been achieved by combining phase partitioning and affinity methods. Cells expressing antigen can be specifically pulled into the top PEG-rich phase of the system by treating the cells with the corresponding antibody coupled to PEG [3,4]. Coupling of PEG to antibodies has been accomplished by activation of the polymer with cyanuric chloride. The subsequent coupling of the activated polymer to the protein requires pH and ionic strength which are non-physiological. In addition, the PEG-antibody is isolated from the unreacted activated PEG before the incubation with the cell mixture.
KeywordsPartition Coefficient Cell Mixture Cyanuric Chloride Countercurrent Distribution Royal Free Hospital
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- 1.P.-Å. Albertsson, Partition of Cell Particles and Macromolecules, 3rd edition, Wiley, Interscience, New York (1985)Google Scholar
- 2.H. Walter, D.E. Brooks and D. Fisher, eds., in: “Partitioning in Aqueous Two-Phase Systems. Theory, Methods, Uses and Applications to Biotechnology,” Academic Press, New York (1985)Google Scholar
- 5.C. Delgado, G.E. Francis and D. Fisher, in preparation.Google Scholar
- 6.K. Nilsson and K. Mosbach, in: “Methods in Enzymology,”, W.D. Jakoby, ed., Academic Press, New York (1984)Google Scholar