ORCID Profile
0000-0002-3006-3171
Current Organisation
University of Miami
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Publisher: Wiley
Date: 29-05-2021
Abstract: Protein‐polymer bioconjugates present a way to make enzymes more efficient and robust for industrial and medicinal applications. While much work has focused on mono‐functional conjugates, that is, conjugates with one type of polymer attached such as poly(ethylene glycol) or poly( N ‐isopropylacrylamide), there is a practical interest in gaining additional functionality by synthesizing well‐defined bifunctional conjugates in a hetero‐arm star copolymer architecture with protein as the core. Using ubiquitin as a model protein, a synthetic scheme is developed to attach two different polymers (oligo(ethylene oxide) methacrylate and N,N‐dimethylacrylamide) directly to the protein surface, using orthogonal conjugation chemistries and grafting‐from by photochemical living radical polymerization techniques. The additional complexity arising from attempts to selectively modify multiple sites led to decreased polymerization performance and indicates that initiators for continuous activator regeneration atom transfer radical polymerization and reversible addition‐fragmentation chain transfer polymerization are not well‐suited to bifunctional bioconjugates applications under the studied conditions. Nonetheless, the polymerization conditions preserve the native fold of the ubiquitin and enable production of a hetero‐arm star protein‐polymer bioconjugate.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8PY01399C
Abstract: This review article discusses the impact of polymer modification on bioconjugate performance, including both activity and stability, with a focus on how the polymer structure and functionality impact these parameters.
Publisher: Wiley
Date: 17-05-2018
Abstract: This review article highlights recent developments in the field of photochemistry and photochemical reversible deactivation radical polymerization applied to aqueous polymerizations. Photochemistry is a topic of significant interest in the fields of organic, polymer, and materials chemistry because it allows challenging reactions to be performed under mild conditions. Aqueous polymerization is of significant interest because water is an environmentally benign solvent, and the use of water enables complex polymer self-assembly and bioconjugation processes to occur. This review focuses on powerful new developments in photochemical aqueous polymerization reactions and their applications to the synthesis of well-defined polymer nano-objects and bioconjugates. It is anticipated that these aqueous photopolymerizations will enable the next generation of self-assembled structures and biohybrid materials to be developed under mild and environmentally friendly conditions.
Publisher: Wiley
Date: 21-06-2021
DOI: 10.1002/POL.20210386
Abstract: An enduring question is: what is the simplest and easiest way to obtain tailored polymers? This communication explores a robust photoiniferter polymerization with only two active ingredients that requires no prior deoxygenation and can be performed on the milliliter scale or sub‐milliliter scale. Rather than leaving headspace in the polymerization vessel or scaling reactions up to fill the vessel, this approach fills the headspace of the reaction vessel with mineral oil or inert solvents. This approach can also be applied to polar monomers in aqueous media, using oil as the inert solvent, or to hydrophobic monomers with water as the inert solvent. This method removes enough ambient oxygen that the photoiniferter reaction proceeds with no deoxygenation step, and achieves high conversion and good molecular weight control in 10–20 h in both aqueous and organic solvents. Complex polymer architectures such as multiblock copolymers and gradient polymers were successfully synthesized by this approach.
Publisher: American Chemical Society (ACS)
Date: 20-02-2020
Publisher: MDPI AG
Date: 05-07-2018
Publisher: American Chemical Society (ACS)
Date: 21-01-2020
Publisher: American Chemical Society (ACS)
Date: 21-09-2022
DOI: 10.1021/ACS.BIOMAC.2C00441
Abstract: The thermophilic cellulase Cel5a from Fervidobacterium nodosum ( Fn Cel5a) was conjugated with neutral, cationic, and anionic polymers of increasing molecular weights. The enzymatic activity toward an anionic soluble cellulose derivative, thermal stability, and functional chemical stability of these bioconjugates were investigated. The results suggest that increasing polymer chain length for polymers compatible with the substrate enhances the positive impact of polymer conjugation on enzymatic activity. Activity enhancements of nearly 100% were observed for bioconjugates with N , N -dimethyl acrylamide (DMAm) and N , N -dimethyl acrylamide-2-( N , N -dimethylamino)ethyl methacrylate (DMAm/DMAEMA) due to proposed polymer-substrate compatibility enabled by potential noncovalent interactions. Double conjugation of two functionally distinct polymers to wild-type and mutated Fn Cel5a using two conjugation methods was achieved. These doubly conjugated bioconjugates exhibited similar thermal stability to the unmodified wild-type enzyme, although enzymatic activity initially gained from conjugation was lost, suggesting that chain length may be a better tool for bioconjugate activity modulation than double conjugation.
Publisher: Elsevier BV
Date: 02-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2PY00602B
Abstract: Polymer based solid-state materials capable of disrupting lipid-bilayers are developed. The materials are mechanically robust and capable of outperforming a 10% small-molecule surfactant and modify filter materials.
Publisher: American Chemical Society (ACS)
Date: 12-01-2017
DOI: 10.1021/ACS.JPCLETT.6B02894
Abstract: Thermodynamic properties of protein unfolding have been extensively studied however, the methods used have typically required significant preparation time and high protein concentrations. Here we present a facile, simple, and parallelized differential scanning fluorimetry (DSF) method that enables thermodynamic parameters of protein unfolding to be extracted. This method assumes a two-state, reversible protein unfolding mechanism and provides the capacity to quickly analyze the biophysical mechanisms of changes in protein stability and to more thoroughly characterize the effect of mutations, additives, inhibitors, or pH. We show the utility of the DSF method by analyzing the thermal denaturation of lysozyme, carbonic anhydrase, chymotrypsin, horseradish peroxidase, and cellulase enzymes. Compared with similar biophysical analyses by circular dichroism, DSF allows for determination of thermodynamic parameters of unfolding while providing greater than 24-fold reduction in experimental time. This study opens the door to rapid characterization of protein stability on low concentration protein s les.
Publisher: American Chemical Society (ACS)
Date: 08-01-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0SC02200D
Abstract: Protein–polymer conjugates are explored using magnetic resonance methods to investigate the conformations of the polymer relative to the protein's surface.
Publisher: American Chemical Society (ACS)
Date: 05-10-2017
DOI: 10.1021/ACS.BIOCONJCHEM.7B00518
Abstract: A thermophilic cellulase, FnCel5a, from Fervidobacterium nodosum was conjugated with various functional polymers including cationic, anionic, and strongly and weakly hydrogen bonding polymers. The activity of FnCel5a toward a high-molecular-weight carboxymethyl cellulose substrate was enhanced by polymer conjugation. Activity enhancements of 50% or greater observed for acrylamide and mixed N,N-dimethyl acrylamide-2-(N,N-dimethylamino)ethyl methacrylate polymers, suggesting that the greatest enhancements were caused by polymers capable of noncovalent interactions with the substrate. The conjugates were found to have nearly identical thermodynamic stability to the native enzyme, as assessed by free energy (ΔG), enthalpy (ΔH), and entropy (TΔS) parameters extracted from differential scanning fluorimetry. Polymers tended to confer comparable tolerance to high concentrations of dimethylformamide, with longer polymers typically enabling higher activity relative to shorter polymers. The new FnCel5a conjugates represent an advance in the production of cellulases that maintain activity at high temperatures or in the presence of denaturing organic solvents.
Publisher: American Chemical Society (ACS)
Date: 03-11-2021
Location: United States of America
No related grants have been discovered for Richard Page.