1. Bioconjugation of papain with poly(N-vinylpyrrolidone): NMR characterization and study of its enzymatic activity
- Author
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Verduzco, L.E., Garcia-Perez, Ana L., Guerrero-Santos, Ramiro, Ledezma-Perez, Antonio, Romero-Garcia, Jorge, and Torres-Lubian, R.
- Subjects
Polymerization -- Analysis ,Nuclear magnetic resonance -- Usage ,Xanthates -- Composition ,Papain -- Composition ,Chemistry - Abstract
A poly(vinylpyrrolidone) end-functionalized with a carboxylic acid group (PVP-[CO.sub.2]H) was synthesized by reversible addition-fragmentation chain transfer (RAFT)/macromolecular design via the interchange of xanthates (MADIX) polymerization mediated by 4-(O-ethylxanthyl)methyl benzoic acid. The molecular weight of the as-synthesized PVP-[CO.sub.2]H was estimated through UV-vis spectroscopy ([M.sub.n(UV-vis)] = 7322 g/mol), gel permeation chromatography (GPC) ([M.sub.n(GPC)] = 8670 g/mol), and [.sup.1]H NMR, ([M.sub.n(NMR)] = 8207 g/mol). The values obtained were close with the theoretical molecular weight ([M.sub.n(th)] = 7925 g/mol). Subsequently, the preformed PVP-[CO.sub.2]H was activated to produce N-succinimidyl poly(vinylpyrrolidone) (PVP-NHS). This precursor was covalently coupled to papain to produce bioconjugate PVP-papain. The functional group modifications in the PVP chain-end were observed by the variations in the chemical shift values by [.sup.1]H and [.sup.13]C NMR and FTIR analysis at each step of the synthesis. The molecular weight of the PVP-papain was obtained by SEC-HPLC and suggests that, on average, four or five chains of PVP-[CO.sub.2]H were attached to one papain molecule. Compared with papain, the PVP-papain exhibited significantly improved catalytic activity, pH, and thermal stability. Additionally, the storage studies showed that the catalytic activity of PVP-papain was about 79% versus the native enzyme (29%), and this activity was maintained even when it was stored for 25 days. Key words: RAFT/MADIX N-vinylpyrrolidone, papain bioconjugation, enzymatic activity, NMR characterization. Nous avons synthetise une poly(vinylpyrrolidone) dont le groupe terminal est une fonction acide carboxylique (PVP-[CO.sub.2]H) par la technique RAFT (polymerisation radicalaire controlee par transfert de chaine reversible par addition-fragmentation)/MADIX (design macromoleculaire par echange de xanthates) facilitee par l'acide 4-(O-ethylxanthyl)methylbenzoique. Le poids moleculaire de la PVP-[CO.sub.2]H synthetisee telle quelle a ete estime par spectroscopie UV-vis ([M.sub.n(UV-vis)] = 7322 g/mol), chromatographie sur gel permeable (GPC) ([M.sub.n(GPC)] = 8670 g/mol) et RMN [.sup.1]H ([M.sub.n(RMN)] = 8207 g/mol). Les valeurs obtenues etaient proches du poids moleculaire theorique ([M.sub.n(th)] = 7925 g/mol). Par la suite, la PVP-[CO.sub.2]H prealablement formee a ete activee pour produire la N-succinimidylpoly(vinylpyrrolidone) (PVP-NHS). Nous avons ensuite fixe ce precurseur a la papaine par couplage covalent pour produire le bioconjugue PVP-papaine. Les variations des valeurs de deplacement chimique en RMN [.sup.1]H et [.sup.13]C et l'analyse des spectres FTIR ont permis de constater les modifications du groupe fonctionnel a l'extremite de chaine de la PVP a chaque etape de la synthese. Nous avons pu estimer le poids moleculaire du bioconjugue PVP-papaine par chromatographie d'exclusion sterique en phase liquide a haute performance (SEC-HPLC), et les resultats semblent indiquer que quatre ou cinq chaines de PVP-[CO.sub.2]H, en moyenne, sont fixees a une molecule de papaine. Comparativement a la papaine, le bioconjugue PVP-papaine a montre une amelioration significative de l'activite catalytique, de la stabilite au pH et de la stabilite thermique. Les etudes de conservation ont egalement revele que l'activite catalytique du bioconjugue PVP-papaine etait d'environ 79%, par rapport a celle de l'enzyme native, qui etait de 29%, et que cette activite etait maintenue meme lorsque le bioconjugue etait entrepose pendant 25 jours. [Traduit par la Redaction] Mots-cles : polymerisation RAFT/MADIX de la N-vinylpyrrolidone, bioconjugaison de la papaine, activite enzymatique, caracterisation par RMN., Introduction The chemical modification of enzymes through bioconjugation with biological or synthetic polymers is an excellent strategy for enhancement of enzymatic activity and stability, and in some cases, it can [...]
- Published
- 2021
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