High‐Temperature Electrochemistry of a Solvent‐Free Myoglobin Melt

Sharma, Kamendra P.; Risbridger, Thomas; Bradley, Kieren; Perriman, Adam W.; Fermı́n, David J.; Mann, Stephen

doi:10.1002/celc.201500094

Cited by 7 publications

(12 citation statements)

References 32 publications

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“…In this paper, we report a novel, generic, and facile method for fabricating protein‐sequestered LC droplets based on the sequestration of surface‐engineered protein–polymer surfactant (PS; poly(ethylene glycol) 4‐nonyl phenyl 3‐sulfopropyl ether potassium salt; M n = 1200) bioconjugates. The PS nanobioconjugates were prepared by electrostatic conjugation of an anionic PS to the surface of the cationized proteins (see Methods in the Supporting Information) . We show that mixing an aqueous solution of the core–shell PS bioconjugates with an aqueous dispersion of 4‐cyano‐4′‐pentylbiphenyl (5CB) nematic LC emulsion droplets results in biomolecule sequestration onto the droplet surface or into the LC interior without protein degradation or structural disruption of the 5CB matrix.…”

Section: Introductionsupporting

confidence: 94%

“…Preparation of Protein–Polymer Surfactant Nanobioconjugates : Preparation of nanobioconjugates of Mb and BSA was carried out via protein surface engineering with polymer surfactant by slight modification of the procedure reported in literature . Briefly, the surface engineering was performed in three steps as shown in Figure b (specifically demonstrated for Mb; for BSA see Supporting Information), and explained as follows:Labeling of Mb or BSA proteins with dyes: RITC (R) and FITC (F) tags were used to image multiple proteins in the LC droplets.…”

Section: Methodsmentioning

confidence: 99%

“…The mixture was stirred slowly (at 300 rpm) in dark condition for 24 h at 10 °C. In order to remove any unlabeled dye, the resultant solution was dialyzed (by using Snakeskin dialysis tubing having MWCO of 10 kDa) against a potassium phosphate buffer (10 × 10 −3 m ; pH 7.4) for 72 h, with intermittent change in the buffer solution after every 6 h. The solution was further centrifuged at 10 000 rpm for 30 min at 10 °C for removal of aggregates, and the supernatant (RITC(R)‐protein or FITC(F)‐protein; proteins: Mb or BSA) was used for the next step.Cationization of dye labeled protein: The cationization of dye‐tagged protein was carried out using well defined procedure from the literature . Briefly, acidic aspartic and glutamic residues at the protein surface were covalently coupled to with N , N ‐dimethyl‐1,3‐propanediamine (diamine), via EDC mediated coupling.…”

Section: Methodsmentioning

confidence: 99%

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Spontaneous Sequestration of Proteins into Liquid Crystalline Microdroplets

Naveenkumar

Mann

Sharma

2018

Adv Materials Inter

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In this work a facile method for fabricating protein‐sequestered liquid crystal (LC) emulsion droplets based on the uptake of surface‐engineered protein–polymer surfactant (PS) core–shell bioconjugates is described. Uptake of myoglobin‐PS, bovine serum albumin‐PS, Zn‐porphyrin myoglobin‐PS, horseradish peroxidase‐PS, and glucose oxidase‐PS occurs without structural or functional degradation, and gives rise to sequestration within the interior or at the surface of 4‐cyano‐4′‐pentylbiphenyl (5CB) nematic droplets depending on the surface modification of the protein‐PS bioconjugates. Differences in uptake behavior are used to achieve the spontaneous positional assembly of multiple proteins in the LC phase, and the use of spatially separated glucose oxidase‐PS and horseradish peroxidase‐PS bioconjugates is demonstrated to produce 5CB based droplets capable of housing an enzyme cascade reaction. This method opens a pathway for the development of bioactive liquid crystal droplets and can have potential applications in the optical sensing of biomolecular substrates.

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Section: Introductionsupporting

confidence: 94%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Spontaneous Sequestration of Proteins into Liquid Crystalline Microdroplets

Naveenkumar

Mann

Sharma

2018

Adv Materials Inter

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“…27 (a) Molecular model of the Mb–surfactant complex. (b) Diagram of the three electrode cell configuration.…”

Section: Design Preparation and Application Of Biomacromolecular LImentioning

confidence: 99%

Liquefaction of Biopolymers: Solvent-free Liquids and Liquid Crystals from Nucleic Acids and Proteins

Liu

Göstl

et al. 2017

Acc. Chem. Res.

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ConspectusBiomacromolecules, such as nucleic acids, proteins, and virus particles, are persistent molecular entities with dimensions that exceed the range of their intermolecular forces hence undergoing degradation by thermally induced bond-scission upon heating. Consequently, for this type of molecule, the absence of a liquid phase can be regarded as a general phenomenon. However, certain advantageous properties usually associated with the liquid state of matter, such as processability, flowability, or molecular mobility, are highly sought-after features for biomacromolecules in a solvent-free environment. Here, we provide an overview over the design principles and synthetic pathways to obtain solvent-free liquids of biomacromolecular architectures approaching the topic from our own perspective of research. We will highlight the milestones in synthesis, including a recently developed general surfactant complexation method applicable to a large variety of biomacromolecules as well as other synthetic principles granting access to electrostatically complexed proteins and DNA.These synthetic pathways retain the function and structure of the biomacromolecules even under extreme, nonphysiological conditions at high temperatures in water-free melts challenging the existing paradigm on the role of hydration in structural biology. Under these conditions, the resulting complexes reveal their true potential for previously unthinkable applications. Moreover, these protocols open a pathway toward the assembly of anisotropic architectures, enabling the formation of solvent-free biomacromolecular thermotropic liquid crystals. These ordered biomaterials exhibit vastly different mechanical properties when compared to the individual building blocks. Beyond the preparative aspects, we will shine light on the unique potential applications and technologies resulting from solvent-free biomacromolecular fluids: From charge transport in dehydrated liquids to DNA electrochromism to biocatalysis in the absence of a protein hydration shell. Moreover, solvent-free biological liquids containing viruses can be used as novel storage and process media serving as a formulation technology for the delivery of highly concentrated bioactive compounds. We are confident that this new class of hybrid biomaterials will fuel further studies and applications of biomacromolecules beyond water and other solvents and in a much broader context than just the traditional physiological conditions.

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“…5 Recently, it was shown that a Mb melt deposited onto highly oriented pyrolytic graphite (HOPG) showed quasi-reversible electrochemical behaviour, 6 and similar behaviour was exhibited up to 150°C on a gold electrode. 7 Little knowledge has been gathered about the redox properties of the protein prior to the lyophilisation step, which could provide information about changes in the environment near the heme. Indeed, the formal reduction potential of the heme is rather sensitive to its chemical environment, which has been a source of controversy in the literature.…”

Section: Introductionmentioning

confidence: 99%

Effect of Bioconjugation on the Reduction Potential of Heme Proteins

Risbridger

Watkins²,

Armstrong³

et al. 2016

Biomacromolecules

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The modification of protein surfaces employing cationic and anionic species enables the assembly of these biomaterials into highly sophisticated hierarchical structures. Such modifications can allow bioconjugates to retain or amplify their functionalities under conditions in which their native structure would be severely compromised. In this work, we assess the effect of this type of bioconjugation on the redox properties of two model heme proteins, that is, cytochrome c (CytC) and myoglobin (Mb). In particular, the work focuses on the sequential modification by 3-dimethylamino propylamine (DMAPA) and 4-nonylphenyl 3-sulfopropyl ether (S1) anionic surfactant. Bioconjugation with DMAPA and S1 are the initial steps in the generation of pure liquid proteins, which remain active in the absence of water and up to temperatures above 150 °C. Thin-layer spectroelectrochemistry reveals that DMAPA cationization leads to a distribution of bioconjugate structures featuring reduction potentials shifted up to 380 mV more negative than the native proteins. Analysis based on circular dichroism, MALDI-TOF mass spectrometry, and zeta potential measurements suggest that the shift in the reduction potentials are not linked to protein denaturation, but to changes in the spin state of the heme. These alterations of the spin states originate from subtle structural changes induced by DMAPA attachment. Interestingly, electrostatic coupling of anionic surfactant S1 shifts the reduction potential closer to that of the native protein, demonstrating that the modifications of the heme electronic configuration are linked to surface charges.

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High‐Temperature Electrochemistry of a Solvent‐Free Myoglobin Melt

Cited by 7 publications

References 32 publications

Spontaneous Sequestration of Proteins into Liquid Crystalline Microdroplets

Spontaneous Sequestration of Proteins into Liquid Crystalline Microdroplets

Liquefaction of Biopolymers: Solvent-free Liquids and Liquid Crystals from Nucleic Acids and Proteins

Effect of Bioconjugation on the Reduction Potential of Heme Proteins

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