Amine Particles

Primary amine-containing polymeric particles are available from a number of manufacturers and have either aliphatic or aryl amine groups on their surface. Occasionally, a particle type may have secondary or tertiary amines present, but these should be avoided for covalent coupling, as primary amines typically give better reaction yields than secondary amines and tertiary amines are unreactive. 

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Coupling to Amine Particles Using Crosslinking Agents... 

Another possible route to coupling ligands to amine particles is to use a bifunctional crosslinking agent to react with the amines and provide another reactive group at the other end to couple with the ligand. In this approach, virtually any reactive group desired can be formed on the... 

A homobifunctional amine-reactive compound can be used initially to modify the amine groups on particles, while leaving the remaining amine-reactive groups available to couple with ligands. This type of reaction must be done with the crosslinker in great excess to prevent polymerization of the amine particles themselves. There must be enough crosslinker present... 

Wash 10 mg of amine particles 3 times with 10 mM sodium phosphate, pH 7.4 (coupling buffer). 

Unlike the use of homobifunctional crosslinkers, heterobifunctional compounds usually don t have to be used in large excess with amine particles to prevent aggregation. This is due to the fact that only one of the ends of the crosslinker can react with the amines on the particles. 

Figure 14.10 The crosslinker SPDP can be reacted with amine particles to create thiol-reactive pyridyl disulfide groups on the surface. Thiol-containing proteins or other thiol molecules can be reacted with these activated particles to result in disulfide linkages, which are reversible by reduction.

To prepare the succinylated carboxylate derivative of the amine particles, wash the particles with water and then into DME... 

Suspend the amine-particles in DMF containing 10 percent succinic anhydride. 

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