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Poly(amidoamine)-BSA conjugates synthesised by Michael addition reaction retained enzymatic activity

Garcia, Diana R., Lavignac, Nathalie (2016) Poly(amidoamine)-BSA conjugates synthesised by Michael addition reaction retained enzymatic activity. Polymer Chemistry, 47 . pp. 7223-7229. ISSN 1759-9954. E-ISSN 1759-9962. (doi:10.1039/c6py01771a) (KAR id:58470)


Polymer-protein conjugates are key to overcome some of the therapeutic protein limitations, including inefficient intracellular delivery. Poly(amidoamine)s are bioresponsive polyelectrolytes, which can form complexes with proteins and promote their delivery into the cytosol of cells. To investigate if conjugation would affect the activity of the protein, two poly(amidoamine)-BSA conjugates were synthesised using a “grafted to” method and Michael addition reaction. Following purification, the conjugates were characterised by electrophoresis, size exclusion chromatography (Mn(C1) = 140.7 kDa ; Mn(C2) = 218.6 kDa) and light scattering (Dh(C1) = 37.5 nm ; Dh(C2) = 75.1 nm). As a result of the conjugation with the cationic polymer, the conjugates had a positive zeta potential (?(C1) = +15.4 mV; ?(C2) = +20.2 mV). TNBS assays demonstrated that 16% to 25% of the protein amine groups were modified and HPLC analysis indicated that the amount of protein in the conjugate was 0.76 mg of BSA/mg of PAA (C1) and 0.43 mg of BSA /mg of PAA (C2). Enzymatic assays indicated the conjugates displayed an esterase activity similar (C1) or reduced ~ 35% (C2) compare to BSA. Altogether the results demonstrated that the conjugation of poly(amidoamine)s to a model protein can lead to the formation of bioconjugates that retain the enzymatic activity of the native protein. Such conjugates could have some application in protein delivery and enzyme engineering for biocatalysis and biosensors.

Item Type: Article
DOI/Identification number: 10.1039/c6py01771a
Uncontrolled keywords: Medway School of Pharmacy
Subjects: Q Science > QD Chemistry > QD431 Organic Chemistry- Biochemistry- Proteins, peptides, amino acids
R Medicine > RM Therapeutics. Pharmacology
Divisions: Divisions > Division of Natural Sciences > Medway School of Pharmacy
Depositing User: Nathalie Lavignac
Date Deposited: 15 Nov 2016 12:14 UTC
Last Modified: 16 Feb 2021 13:38 UTC
Resource URI: (The current URI for this page, for reference purposes)

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