The Chemical Modification of Proteins, Haptens, and Solid Supports

摘要: Publisher Summary This chapter discusses the chemical modification of proteins, haptens, and solid supports. The main contribution to proteins–solid supports type coupling reaction certainly comes from field immobilized enzymes. same methods can be applied as for provided support is activated. activation proteins often leads unwanted cross-linking macromolecules. Affinity chromatography on hapten-derivatized polysaccharide beads widely used purification specific antibodies. cyanogen bromide-activated are commercially available derivatized readily with any amine. To avoid it advantageous activate hapten rather than some functional groups protein molecule. Cyanogen bromide requires a high pH (10.5–11.5), but an amine activated proceeds easily in 0.1 M NaHCO 3 . method essentially preparation affinity columns. carboxylic acid amide formation, carboxyl group Activation case means formation intermediate O -acylisourea. cannot isolated because unstable aqueous solutions. However, reacts presence amines form desired amide. first part this two-step mechanism catalyzed by protonation one imide nitrogen and, therefore, slightly acidic conditions, whereas second step involves free Under these not surprising that optimal rates over fairly large range.