Smart polymer-protein conjugates

Shimoboji, T., Ding, Z. L., Stayton, P. S. and Hoffinan, A. S. (2001) Mechanistic Investigation of Smart Polymer-Protein Conjugates, Bioconjugate Chem., 12, 314—9. 

The ability of smart polymers to form in situ heterogeneous systems is exploited in affinity precipitation (Fig. 4). The technique is based on using a conjugate of a smart polymer that has a covalently coupled biorecognition moiety, that is, a ligand specific for a target protein. The conjugate forms a complex with... 

The preparation of polymer-protein conjugates is possible by two mechanisms random and site-specific conjugation. In the case of random conjugation, the polymer is usually linked to lysine groups of the proteins. Site-specific conjugation, on the other hand, is based on the insertion of cysteine residues with exposed thiol groups which react preferentially with vinyl or vinyl sulfon groups of the smart polymers (Hoffman and Stayton, 2007). 

Heredia KL, Bontempo D, Ly T, Byers JT, Halstenberg S, Maynard HD. In situ preparation of protein smart polymer conjugates with retention of bioactivity. J Am Chem Soc 2005 127 16955-16960. 

The conjugation of proteins to stimuli responsive polymers are used in the field of protein isolation and separation [29,30]. The ability of some polymers to undergo a reversible change in response to an external physical, chemical, or biochemical stimulus gave them the name smart polymers [31]. Different stimuli have been utilized, such as temperature, light, ionic strength, or electric field for physical factors, or pH and specific ions for chemical triggers or metabolites for biochemical reactions [32, 33]. 

Another approach consists in using smart polymers for a triggered protein precipitation, which can be used for purification of proteins. For example, the enzyme trypsin was coupled with poly(Al-isopropylacrylamide) (PNIPAM). After successful conjugation, the protein could be precipitated by heating above the lower critical solution temperature (LCST) of the polymer [39, 40]. 

Cell-sensing biomacromolecules responsive Smart protein-polymer conjugates ... 

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