ITABLE 414 Some functional groups attached to column matrices to purify specific proteins

Functional Group on Matrix

Example Protein

Enzyme cofactor Lectins

Protein A or G Hydrophobic group Metal ions Triazine dye Heparin DEAE

Enzyme Glycoprotein

Immunoglobulin, IgG class of antibody

Various proteins with hydrophobic domain

Metal ion binding proteins (metalloproteins)

Dehydrogenases, kinases, and other proteins

Coagulation factors, protein kinases

Most proteins with domains that exhibit partial charge protein with small amounts of contaminants and inactive protein fragments. Recombinant protein consitutes more than 90% of the purified material.

A final purification, known as the polishing step, is designed to remove trace contaminants and impurities so that a biologically active recombinant protein with a safety profile suitable for pharmaceutical application is obtained. Contaminants removed by polishing are usually fragments or inactive forms of recombinant protein and trace amounts of endotoxin. The chromatography systems used for intermediate and final purification are largely similar, but differ in capacity and separation performance. Chromatography systems for final purifications demand high performance even at the cost of a lower capacity than the column used for intermediate purification. High separation performance is needed to minimize contaminant carryover into the recombinant product destined for pharmaceutical use.

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