Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers
Non-covalent polymer-protein conjugation is emerging as a potential route to improve pharmacokinetics and pharmacodynamics of protein therapeutics. In this study, a family of structurally related block copolymers of mPEG2k - poly(glutamic acid) with linear A-B (mPEG2k-lin-polyGA) and miktoarm A-B3 (...
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| Format: | Article |
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Royal Society of Chemistry
2017
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| Online Access: | https://eprints.nottingham.ac.uk/41847/ |
| _version_ | 1848796367236890624 |
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| author | Nieto-Orellana, Alejandro Di Antonio, Marco Conte, Claudia Falcone, Franco H. Bosquillon, Cynthia Childerhouse, Nick Mantovani, Giuseppe Stolnik, Snow |
| author_facet | Nieto-Orellana, Alejandro Di Antonio, Marco Conte, Claudia Falcone, Franco H. Bosquillon, Cynthia Childerhouse, Nick Mantovani, Giuseppe Stolnik, Snow |
| author_sort | Nieto-Orellana, Alejandro |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Non-covalent polymer-protein conjugation is emerging as a potential route to improve pharmacokinetics and pharmacodynamics of protein therapeutics. In this study, a family of structurally related block copolymers of mPEG2k - poly(glutamic acid) with linear A-B (mPEG2k-lin-polyGA) and miktoarm A-B3 ((mPEG2k-mik-(polyGA)3) structure was synthesised by N-carboxyanhydride (NCA) ring-opening polymerisation to assess the effect of macromolecular topology of the copolymers on polymer-protein complexation. The data illustrate that the synthesised copolymers are capable of complexing a model protein, lysozyme, at optimal pH conditions through non-covalent interactions, with complexation efficiencies depending on the copolymers composition and molecular architecture. In native gel electrophoresis experiments, linear mPEG2k-lin-GA10 copolymer, possessing a short polyanionic polyGA block, shows a low level of complexation, which does not change when the number of polyGA branches of the same size is increased, using a miktoarm mPEG2k-mik-(GA10)3 copolymer. However, enhanced complexation is observed when the same number of ionisable GA units (30) are displayed on a linear macromolecular scaffold; mPEG2k-mik-(GA10)3 vs. mPEG2k-lin-GA30. Again complexation efficiency did not increase when the number of complexing polyGA branches were increased; mPEG2k-lin-GA30 vs. mPEG2k-mik-(GA30)3. Nanoparticle tracking analysis (NTA) showed that the copolymer-protein complexes possessed hydrodynamic diameters in the 50-200 nm range, suggesting a degree of control in the assembly process. Sequestration of lysozyme within polymer complexes resulted in a decrease in its apparent enzymatic activity, which was re-established on the complexes dissociation upon a treatment with competitive complexant. Intrinsic fluorescence and circular dichroism (CD) studies suggested structural conformation of the protein was not altered following complexation with mPEG2k-polyGA copolymers. Taken together, these results provide an initial structure-function relationship for protein-complexing mPEG2k-polyGA copolymers with variable macromolecular topology, opening the way for their future application in biological and biomedical studies. |
| first_indexed | 2025-11-14T19:46:51Z |
| format | Article |
| id | nottingham-41847 |
| institution | University of Nottingham Malaysia Campus |
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| last_indexed | 2025-11-14T19:46:51Z |
| publishDate | 2017 |
| publisher | Royal Society of Chemistry |
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| spelling | nottingham-418472020-05-04T18:38:22Z https://eprints.nottingham.ac.uk/41847/ Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers Nieto-Orellana, Alejandro Di Antonio, Marco Conte, Claudia Falcone, Franco H. Bosquillon, Cynthia Childerhouse, Nick Mantovani, Giuseppe Stolnik, Snow Non-covalent polymer-protein conjugation is emerging as a potential route to improve pharmacokinetics and pharmacodynamics of protein therapeutics. In this study, a family of structurally related block copolymers of mPEG2k - poly(glutamic acid) with linear A-B (mPEG2k-lin-polyGA) and miktoarm A-B3 ((mPEG2k-mik-(polyGA)3) structure was synthesised by N-carboxyanhydride (NCA) ring-opening polymerisation to assess the effect of macromolecular topology of the copolymers on polymer-protein complexation. The data illustrate that the synthesised copolymers are capable of complexing a model protein, lysozyme, at optimal pH conditions through non-covalent interactions, with complexation efficiencies depending on the copolymers composition and molecular architecture. In native gel electrophoresis experiments, linear mPEG2k-lin-GA10 copolymer, possessing a short polyanionic polyGA block, shows a low level of complexation, which does not change when the number of polyGA branches of the same size is increased, using a miktoarm mPEG2k-mik-(GA10)3 copolymer. However, enhanced complexation is observed when the same number of ionisable GA units (30) are displayed on a linear macromolecular scaffold; mPEG2k-mik-(GA10)3 vs. mPEG2k-lin-GA30. Again complexation efficiency did not increase when the number of complexing polyGA branches were increased; mPEG2k-lin-GA30 vs. mPEG2k-mik-(GA30)3. Nanoparticle tracking analysis (NTA) showed that the copolymer-protein complexes possessed hydrodynamic diameters in the 50-200 nm range, suggesting a degree of control in the assembly process. Sequestration of lysozyme within polymer complexes resulted in a decrease in its apparent enzymatic activity, which was re-established on the complexes dissociation upon a treatment with competitive complexant. Intrinsic fluorescence and circular dichroism (CD) studies suggested structural conformation of the protein was not altered following complexation with mPEG2k-polyGA copolymers. Taken together, these results provide an initial structure-function relationship for protein-complexing mPEG2k-polyGA copolymers with variable macromolecular topology, opening the way for their future application in biological and biomedical studies. Royal Society of Chemistry 2017-03-21 Article PeerReviewed Nieto-Orellana, Alejandro, Di Antonio, Marco, Conte, Claudia, Falcone, Franco H., Bosquillon, Cynthia, Childerhouse, Nick, Mantovani, Giuseppe and Stolnik, Snow (2017) Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers. Polymer Chemistry, 8 (14). pp. 2210-2220. ISSN 1759-9962 http://pubs.rsc.org/en/content/articlelanding/2017/py/c7py00169j#!divAbstract doi:10.1039/C7PY00169J doi:10.1039/C7PY00169J |
| spellingShingle | Nieto-Orellana, Alejandro Di Antonio, Marco Conte, Claudia Falcone, Franco H. Bosquillon, Cynthia Childerhouse, Nick Mantovani, Giuseppe Stolnik, Snow Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers |
| title | Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers |
| title_full | Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers |
| title_fullStr | Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers |
| title_full_unstemmed | Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers |
| title_short | Effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mPEG-poly(glutamic acid) copolymers |
| title_sort | effect of polymer topology on non-covalent polymer-protein complexation: miktoarm versus linear mpeg-poly(glutamic acid) copolymers |
| url | https://eprints.nottingham.ac.uk/41847/ https://eprints.nottingham.ac.uk/41847/ https://eprints.nottingham.ac.uk/41847/ |