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Chemical Modification of Glycoproteins' Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase. Polymers (Basel) 2021; 13:polym13223875. [PMID: 34833174 PMCID: PMC8621032 DOI: 10.3390/polym13223875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/02/2021] [Accepted: 11/07/2021] [Indexed: 11/17/2022] Open
Abstract
Zeolitic imidazolate framework-8 (ZIF-8) is widely used as a protective coating to encapsulate proteins via biomimetic mineralization. The formation of nucleation centers and further biocomposite crystal growth is entirely governed by the pure electrostatic interactions between the protein’s surface and the positively charged Zn(II) metal ions. It was previously shown that enhancing these electrostatic interactions by a chemical modification of surface amino acid residues can lead to a rapid biocomposite crystal formation. However, a chemical modification of carbohydrate components by periodate oxidation for glycoproteins can serve as an alternative strategy. In the present study, an industrially important enzyme glucose oxidase (GOx) was selected as a model system. Periodate oxidation of GOx by 2.5 mM sodium periodate increased negative charge on the enzyme molecule, from −10.2 to −36.9 mV, as shown by zeta potential measurements and native PAGE electrophoresis. Biomineralization experiments with oxidized GOx resulted in higher specific activity, effectiveness factor, and higher thermostability of the ZIF-8 biocomposites. Periodate oxidation of carbohydrate components for glycoproteins can serve as a facile and general method for facilitating the biomimetic mineralization of other industrially relevant glycoproteins.
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Ziegler CE, Graf M, Nagaoka M, Lehr H, Goepferich AM. In Situ Forming iEDDA Hydrogels with Tunable Gelation Time Release High-Molecular Weight Proteins in a Controlled Manner over an Extended Time. Biomacromolecules 2021; 22:3223-3236. [PMID: 34270216 DOI: 10.1021/acs.biomac.1c00299] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Off-target interactions between reactive hydrogel moieties and drug cargo as well as slow reaction kinetics and the absence of controlled protein release over an extended period of time are major drawbacks of chemically cross-linked hydrogels for biomedical applications. In this study, the inverse electron demand Diels-Alder (iEDDA) reaction between norbornene- and tetrazine-functionalized eight-armed poly(ethylene glycol) (PEG) macromonomers was used to overcome these obstacles. Oscillatory shear experiments revealed that the gel point of a 15% (w/v) eight-armed PEG hydrogel with a molecular weight of 10 kDa was less than 15 s, suggesting the potential for fast in situ gelation. However, the high-speed reaction kinetics result in a risk of premature gel formation that complicates the injection process. Therefore, we investigated the effect of polymer concentration, temperature, and chemical structure on the gelation time. The cross-linking reaction was further characterized regarding bioorthogonality. Only 11% of the model protein lysozyme was found to be PEGylated by the iEDDA reaction, whereas 51% interacted with the classical Diels-Alder reaction. After determination of the mesh size, fluorescein isothiocyanate-dextran was used to examine the release behavior of the hydrogels. When glucose oxidase was embedded into 15% (w/v) hydrogels, a controlled release over more than 250 days was achieved. Overall, the PEG-based hydrogels cross-linked via the fast iEDDA reaction represent a promising material for the long-term administration of biologics.
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Affiliation(s)
- Christian E Ziegler
- Department of Pharmaceutical Technology, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany
| | - Moritz Graf
- Department of Pharmaceutical Technology, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany
| | - Makoto Nagaoka
- Department of Pharmaceutical Technology, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany
| | - Heike Lehr
- Department of Pharmaceutical Technology, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany
| | - Achim M Goepferich
- Department of Pharmaceutical Technology, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany
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Thomas B, Ohde D, Matthes S, Engelmann C, Bubenheim P, Terasaka K, Schlüter M, Liese A. Comparative investigation of fine bubble and macrobubble aeration on gas utility and biotransformation productivity. Biotechnol Bioeng 2020; 118:130-141. [PMID: 32886350 DOI: 10.1002/bit.27556] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/06/2020] [Accepted: 08/30/2020] [Indexed: 01/02/2023]
Abstract
The sufficient provision of oxygen is mandatory for enzymatic oxidations in aqueous solution, however, in process optimization this still is a bottleneck that cannot be overcome with the established methods of macrobubble aeration. Providing higher mass transfer performance through microbubble aerators, inefficient aeration can be overcome or improved. Investigating the mass transport performance in a model protein solution, the microbubble aeration results in higher kL a values related to the applied airstream in comparison with macrobubble aeration. Comparing the aerators at identical kL a of 160 and 60 1/h, the microbubble aeration is resulting in 25 and 44 times enhanced gas utility compared with aeration with macrobubbles. To prove the feasibility of microbubbles in biocatalysis, the productivity of a glucose oxidase catalyzed biotransformation is compared with macrobubble aeration as well as the gas-saving potential. In contrast to the expectation that the same productivities are achieved at identically applied kL a, microbubble aeration increased the gluconic acid productivity by 32% and resulted in 41.6 times higher oxygen utilization. The observed advantages of microbubble aeration are based on the large volume-specific interfacial area combined with a prolonged residence time, which results in a high mass transfer performance, less enzyme deactivation by foam formation, and reduced gas consumption. This makes microbubble aerators favorable for application in biocatalysis.
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Affiliation(s)
- Benjamin Thomas
- Hamburg University of Technology, Institute of Technical Biocatalysis, Hamburg, Germany
| | - Daniel Ohde
- Hamburg University of Technology, Institute of Technical Biocatalysis, Hamburg, Germany
| | - Simon Matthes
- Hamburg University of Technology, Institute of Multiphase Flows, Hamburg, Germany
| | - Claudia Engelmann
- Hamburg University of Technology, Institute of Technical Biocatalysis, Hamburg, Germany
| | - Paul Bubenheim
- Hamburg University of Technology, Institute of Technical Biocatalysis, Hamburg, Germany
| | - Koichi Terasaka
- Department of Applied Chemistry, Keio University, Yokohama, Japan
| | - Michael Schlüter
- Hamburg University of Technology, Institute of Multiphase Flows, Hamburg, Germany
| | - Andreas Liese
- Hamburg University of Technology, Institute of Technical Biocatalysis, Hamburg, Germany
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Hu C, Annese VF, Velugotla S, Al-Rawhani M, Cheah BC, Grant J, Barrett MP, Cumming DRS. Disposable Paper-on-CMOS Platform for Real-Time Simultaneous Detection of Metabolites. IEEE Trans Biomed Eng 2020; 67:2417-2426. [PMID: 32011243 DOI: 10.1109/tbme.2019.2962239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Early stage diagnosis of sepsis without overburdening health services is essential to improving patient outcomes. METHODS A fast and simple-to-use platform that combines an integrated circuit with paper microfluidics for simultaneous detection of multiple-metabolites appropriate for diagnostics was presented. Paper based sensors are a primary candidate for widespread deployment of diagnostic or test devices. However, the majority of devices today use a simple paper strip to detect a single marker using the reflectance of light. However, for many diseases such as sepsis, one biomarker is not sufficient to make a unique diagnosis. In this work multiple measurements are made on patterned paper simultaneously. Using laser ablation to fabricate microfluidic channels on paper provides a flexible and direct approach for mass manufacture of disposable paper strips. A reusable photodiode array on a complementary metal oxide semiconductor chip is used as the transducer. RESULTS The system measures changes in optical absorbance in the paper to achieve a cost-effective and easily implemented system that is capable of multiple simultaneous assays. Potential sepsis metabolite biomarkers glucose and lactate have been studied and quantified with the platform, achieving sensitivity within the physiological range in human serum. CONCLUSION We have detailed a disposable paper-based CMOS photodiode sensor platform for real-time simultaneous detection of metabolites for diseases such as sepsis. SIGNIFICANCE A combination of a low-cost paper strip with microfluidic channels and a sensitive CMOS photodiode sensor array makes our platform a robust portable and inexpensive biosensing device for multiple diagnostic tests in many different applications.
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Wang Y, Jonkute R, Lindmark H, Keighron JD, Cans AS. Molecular Crowding and a Minimal Footprint at a Gold Nanoparticle Support Stabilize Glucose Oxidase and Boost Its Activity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:37-46. [PMID: 31865701 DOI: 10.1021/acs.langmuir.9b02863] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Enzymes conjugated to nanomaterials are used in the design of various biotechnologies. In the development of biosensors, surface modifications with the enzyme glucose oxidase (GOx) serve to aid the detection of blood glucose. In order to optimize sensor effectiveness, the enzyme tertiary structure needs to be preserved upon immobilization to retain the enzyme's catalytic activity. Because of the nature of GOx, it suffers from a tendency to denature when immobilized at a solid surface; hence, methods to optimize enzyme stability are of great importance. Here, we introduce the study of the interaction of GOx to the highly curved surface of 20 nm gold nanoparticles (AuNP) with an absorbed monolayer coating of enzyme as determined by flocculation assays and quantification of immobilized GOx at the nanoparticle surface. Enzyme crowding was determined by comparing the number of enzymes that bind to how many can physically fit. These measurements show how placing a monolayer of enzyme where the enzyme spreads thin at the AuNP surface still provides stable catalytic performance of up to 14 days compared to enzymes free in solution. Moreover, by the increasing enzyme density via increasing the amount of GOx present in solution during the GOx/AuNP conjugation step creates a molecularly crowded environment at the highly curved nanoparticle surface. This limits the size of the enzyme footprint for attachment and shows that the activity per enzyme can be enhanced up to 300%. This is of great importance for implementing stable and sensitive sensor technologies that are constructed by enzyme-based nanoparticle scaffolds. Here, we show by using the conditions that maintain GOx structure and function when limiting the enzyme coating to an ultrathin layer, the design and construction of an ultrafast responding diagnostic sensor technology for glucose can be achieved, which is crucial for monitoring rapid fluctuations of, for instance, glucose in the brain.
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Affiliation(s)
- Yuanmo Wang
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , Gothenburg SE-412 96 , Sweden
| | - Rima Jonkute
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , Gothenburg SE-412 96 , Sweden
| | - Hampus Lindmark
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , Gothenburg SE-412 96 , Sweden
| | - Jacqueline D Keighron
- Department of Chemical and Biological Sciences , New York Institute of Technology , Old Westbury , New York 11568 , United States
| | - Ann-Sofie Cans
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Kemigården 4 , Gothenburg SE-412 96 , Sweden
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Wang X, Kim JH, Choi YB, Kim HH, Kim CJ. Fabrication of optimally configured layers of SWCNTs, gold nanoparticles, and glucose oxidase on ITO electrodes for high-power enzymatic biofuel cells. KOREAN J CHEM ENG 2019. [DOI: 10.1007/s11814-019-0278-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Zhao S, Völkner J, Riedel M, Witte G, Yue Z, Lisdat F, Parak WJ. Multiplexed Readout of Enzymatic Reactions by Means of Laterally Resolved Illumination of Quantum Dot Electrodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:21830-21839. [PMID: 31117441 DOI: 10.1021/acsami.9b03990] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Triggering electrochemical reactions with light provides a powerful tool for the control of complex reaction schemes on photoactive electrodes. Here, we report on the light-directed, multiplexed detection of enzymatic substrates using a nonstructured gold electrode modified with CdSe/ZnS quantum dots (QDs) and two enzymes, glucose oxidase (GOx) and sarcosine oxidase (SOx). While QDs introduce visible-light sensitivity into the electrode architecture, GOx and SOx allow for a selective conversion of glucose and sarcosine, respectively. For the QD immobilization to the gold electrode, a linker-assisted approach using trans-4,4'-stilbenedithiol has been used, resulting in the generation of a photocurrent. Subsequently, GOx and SOx have been immobilized in spatially separated spots onto the QD electrode. For the local readout of the QD electrode, a new measurement setup has been developed by moving a laser pointer across the surface to defined positions on the chip surface. The amplitudes of the photocurrents upon illumination of the GOx or SOx spot depend in a concentration-dependent manner on the presence of glucose and sarcosine, respectively. This measurement also allows for a selective detection in the presence of other substances. The setup demonstrates the feasibility of multiplexed measurements of enzymatic reactions using a focused light pointer, resulting in an illumination area with a diameter of 0.3 mm for analyzing spots of different enzymes. Moving the laser pointer in the x- and y-direction and simultaneously detecting the local photocurrent also allow a spatial imaging of enzyme immobilization. Here, not only the spot dimensions but also the activity of the enzyme can be verified.
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Affiliation(s)
- Shuang Zhao
- Fachbereich Physik, CHyN , Universität Hamburg , 22761 Hamburg , Germany
| | - Johannes Völkner
- Fachbereich Physik , Philipps-Universität Marburg , Renthof 5 , 35032 Marburg , Germany
| | - Marc Riedel
- Biosystems Technology, Institute of Life Sciences and Biomedical Technologies , Technical University of Applied Sciences Wildau , Hochschulring 1 , 15745 Wildau , Germany
| | - Gregor Witte
- Fachbereich Physik , Philipps-Universität Marburg , Renthof 5 , 35032 Marburg , Germany
| | - Zhao Yue
- Department of Microelectronics , Nankai University , 300350 Tianjin , China
| | - Fred Lisdat
- Biosystems Technology, Institute of Life Sciences and Biomedical Technologies , Technical University of Applied Sciences Wildau , Hochschulring 1 , 15745 Wildau , Germany
| | - Wolfgang J Parak
- Fachbereich Physik, CHyN , Universität Hamburg , 22761 Hamburg , Germany
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8
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Bolivar JM, Mannsberger A, Thomsen MS, Tekautz G, Nidetzky B. Process intensification for O 2 -dependent enzymatic transformations in continuous single-phase pressurized flow. Biotechnol Bioeng 2019; 116:503-514. [PMID: 30512199 PMCID: PMC6590253 DOI: 10.1002/bit.26886] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/16/2018] [Accepted: 11/29/2018] [Indexed: 12/24/2022]
Abstract
Oxidative O2 -dependent biotransformations are promising for chemical synthesis, but their development to an efficiency required in fine chemical manufacturing has proven difficult. General problem for process engineering of these systems is that thermodynamic and kinetic limitations on supplying O2 to the enzymatic reaction combine to create a complex bottleneck on conversion efficiency. We show here that continuous-flow microreactor technology offers a comprehensive solution. It does so by expanding the process window to the medium pressure range (here, ≤34 bar) and thus enables biotransformations to be conducted in a single liquid phase at boosted concentrations of the dissolved O2 (here, up to 43 mM). We take reactions of glucose oxidase and d-amino acid oxidase as exemplary cases to demonstrate that the pressurized microreactor presents a powerful engineering tool uniquely apt to overcome restrictions inherent to the individual O2 -dependent transformation considered. Using soluble enzymes in liquid flow, we show reaction rate enhancement (up to six-fold) due to the effect of elevated O2 concentrations on the oxidase kinetics. When additional catalase was used to recycle dissolved O2 from the H2 O2 released in the oxidase reaction, product formation was doubled compared to the O2 supplied, in the absence of transfer from a gas phase. A packed-bed reactor containing oxidase and catalase coimmobilized on porous beads was implemented to demonstrate catalyst recyclability and operational stability during continuous high-pressure conversion. Product concentrations of up to 80 mM were obtained at low residence times (1-4 min). Up to 360 reactor cycles were performed at constant product release and near-theoretical utilization of the O2 supplied. Therefore, we show that the pressurized microreactor is practical embodiment of a general reaction-engineering concept for process intensification in enzymatic conversions requiring O2 as the cosubstrate.
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Affiliation(s)
- Juan M Bolivar
- Austrian Centre of Industrial Biotechnology (ACIB), Graz, Austria.,Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Alexander Mannsberger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
| | | | - Günter Tekautz
- Microinnova Engineering GmbH, Allerheiligen bei Wildon, Austria
| | - Bernd Nidetzky
- Austrian Centre of Industrial Biotechnology (ACIB), Graz, Austria.,Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
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9
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Sanli S, Celik EG, Demir B, Gumus ZP, Ilktac R, Aksuner N, Demirkol DO, Timur S. Magnetic Nanofiber Layers as a Functional Surface for Biomolecule Immobilization and One-Use ‘Sensing in-a-Drop’ Applications. ChemistrySelect 2018. [DOI: 10.1002/slct.201802602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Serdar Sanli
- Biochemistry Department; Faculty of Science; Ege University, İzmir; Turkey
| | - Emine Guler Celik
- Biochemistry Department; Faculty of Science; Ege University, İzmir; Turkey
| | - Bilal Demir
- CNRS Enzyme and Cell Engineering Laboratory; Sorbonne Universités, Université de Technologie de Compiègne, Rue Roger Couttolenc, CS 60319; 60203 Compiègne Cedex France
| | - Z. Pinar Gumus
- Central Research Testing and Analyses Laboratory Research and Application Centre; Ege University; 35100-Bornova/Izmir Turkey
| | - Raif Ilktac
- Central Research Testing and Analyses Laboratory Research and Application Centre; Ege University; 35100-Bornova/Izmir Turkey
| | - Nur Aksuner
- Chemistry Department; Faculty of Science; Ege University; Izmir Turkey
| | | | - Suna Timur
- Biochemistry Department; Faculty of Science; Ege University, İzmir; Turkey
- Central Research Testing and Analyses Laboratory Research and Application Centre; Ege University; 35100-Bornova/Izmir Turkey
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10
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Xu Y, Liu SY, Li J, Zhang L, Chen D, Zhang JP, Xu Y, Dai Z, Zou X. Real-Time Sensing of TET2-Mediated DNA Demethylation In Vitro by Metal–Organic Framework-Based Oxygen Sensor for Mechanism Analysis and Stem-Cell Behavior Prediction. Anal Chem 2018; 90:9330-9337. [DOI: 10.1021/acs.analchem.8b01941] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Yuzhi Xu
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Si-Yang Liu
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Jie Li
- Fudan University Shanghai Cancer Center, Institute of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, P. R. China
| | - Li Zhang
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Danping Chen
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Jie-Peng Zhang
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institute of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, P. R. China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P. R. China
| | - Zong Dai
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Xiaoyong Zou
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. China
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Counting the number of enzymes immobilized onto a nanoparticle-coated electrode. Anal Bioanal Chem 2017; 410:1775-1783. [PMID: 29279991 PMCID: PMC5807476 DOI: 10.1007/s00216-017-0829-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/30/2017] [Accepted: 12/13/2017] [Indexed: 11/24/2022]
Abstract
To immobilize enzymes at the surface of a nanoparticle-based electrochemical sensor is a common method to construct biosensors for non-electroactive analytes. Studying the interactions between the enzymes and nanoparticle support is of great importance in optimizing the conditions for biosensor design. This can be achieved by using a combination of analytical methods to carefully characterize the enzyme nanoparticle coating at the sensor surface while studying the optimal conditions for enzyme immobilization. From this analytical approach, it was found that controlling the enzyme coverage to a monolayer was a key factor to significantly improve the temporal resolution of biosensors. However, these characterization methods involve both tedious methodologies and working with toxic cyanide solutions. Here we introduce a new analytical method that allows direct quantification of the number of immobilized enzymes (glucose oxidase) at the surface of a gold nanoparticle coated glassy carbon electrode. This was achieved by exploiting an electrochemical stripping method for the direct quantification of the density and size of gold nanoparticles coating the electrode surface and combining this information with quantification of fluorophore-labeled enzymes bound to the sensor surface after stripping off their nanoparticle support. This method is both significantly much faster compared to previously reported methods and with the advantage that this method presented is non-toxic. A new analytical method for direct quantification of the number of enzymes immobilized at the surface of gold nanoparticles covering a glassy carbon electrode using anodic stripping and fluorimetry ![]()
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Zubkovs V, Schuergers N, Lambert B, Ahunbay E, Boghossian AA. Mediatorless, Reversible Optical Nanosensor Enabled through Enzymatic Pocket Doping. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1701654. [PMID: 28940888 DOI: 10.1002/smll.201701654] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/05/2017] [Indexed: 05/27/2023]
Abstract
Single-walled carbon nanotubes (SWCNTs) exhibit intrinsic near-infrared fluorescence that benefits from indefinite photostability and tissue transparency, offering a promising basis for in vivo biosensing. Existing SWCNT optical sensors that rely on charge transfer for signal transduction often require exogenous mediators that compromise the stability and biocompatibility of the sensors. This study presents a reversible, mediatorless, near-infrared glucose sensor based on glucose oxidase-wrapped SWCNTs (GOx-SWCNTs). GOx-SWCNTs undergo a selective fluorescence increase in the presence of aldohexoses, with the strongest response toward glucose. When incorporated into a custom-built membrane device, the sensor demonstrates a monotonic increase in initial response rates with increasing glucose concentrations between 3 × 10-3 and 30 × 10-3 m and an apparent Michaelis-Menten constant of KM (app) ≈ 13.9 × 10-3 m. A combination of fluorescence, absorption, and Raman spectroscopy measurements suggests a fluorescence enhancement mechanism based on localized enzymatic doping of SWCNT defect sites that does not rely on added mediators. Removal of glucose reverses the doping effects, resulting in full recovery of the fluorescence intensity. The cyclic addition and removal of glucose is shown to successively enhance and recover fluorescence, demonstrating reversibility that serves as a prerequisite for continuous glucose monitoring.
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Affiliation(s)
- Vitalijs Zubkovs
- École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - Nils Schuergers
- École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - Benjamin Lambert
- École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - Esra Ahunbay
- École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
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13
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Jambrec D, Lammers K, Bobrowski T, Pöller S, Schuhmann W, Ruff A. Amperometric Detection of dsDNA Using an Acridine-Orange-Modified Glucose Oxidase. Chempluschem 2017; 82:1311-1314. [DOI: 10.1002/cplu.201700279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/19/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Daliborka Jambrec
- Analytical Chemistry-Center for Electrochemical Sciences (CES); Ruhr-Universität Bochum; Universitätsstrasse 150 44780 Bochum Germany
| | - Klaus Lammers
- Analytical Chemistry-Center for Electrochemical Sciences (CES); Ruhr-Universität Bochum; Universitätsstrasse 150 44780 Bochum Germany
| | - Tim Bobrowski
- Analytical Chemistry-Center for Electrochemical Sciences (CES); Ruhr-Universität Bochum; Universitätsstrasse 150 44780 Bochum Germany
| | - Sascha Pöller
- Analytical Chemistry-Center for Electrochemical Sciences (CES); Ruhr-Universität Bochum; Universitätsstrasse 150 44780 Bochum Germany
| | - Wolfgang Schuhmann
- Analytical Chemistry-Center for Electrochemical Sciences (CES); Ruhr-Universität Bochum; Universitätsstrasse 150 44780 Bochum Germany
| | - Adrian Ruff
- Analytical Chemistry-Center for Electrochemical Sciences (CES); Ruhr-Universität Bochum; Universitätsstrasse 150 44780 Bochum Germany
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14
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Ward WK, Heinrich G, Breen M, Benware S, Vollum N, Morris K, Knutsen C, Kowalski JD, Campbell S, Biehler J, Vreeke MS, Vanderwerf SM, Castle JR, Cargill RS. An Amperometric Glucose Sensor Integrated into an Insulin Delivery Cannula: In Vitro and In Vivo Evaluation. Diabetes Technol Ther 2017; 19:226-236. [PMID: 28221814 PMCID: PMC5399735 DOI: 10.1089/dia.2016.0407] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Labeling prohibits delivery of insulin at the site of subcutaneous continuous glucose monitoring (CGM). Integration of the sensing and insulin delivery functions into a single device would likely increase the usage of CGM in persons with type 1 diabetes. METHODS To understand the nature of such interference, we measured glucose at the site of bolus insulin delivery in swine using a flexible electrode strip that was laminated to the outer wall of an insulin delivery cannula. In terms of sensing design, we compared H2O2-measuring sensors biased at 600 mV with redox mediator-type sensors biased at 175 mV. RESULTS In H2O2-measuring sensors, but not in sensors with redox-mediated chemistry, a spurious rise in current was seen after insulin lis-pro boluses. This prolonged artifact was accompanied by electrode poisoning. In redox-mediated sensors, the patterns of sensor signals acquired during delivery of saline and without any liquid delivery were similar to those acquired during insulin delivery. CONCLUSION Considering in vitro and in vivo findings together, it became clear that the mechanism of interference is the oxidation, at high bias potentials, of phenolic preservatives present in insulin formulations. This effect can be avoided by the use of redox mediator chemistry using a low bias potential.
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Affiliation(s)
| | | | - Matthew Breen
- Pacific Diabetes Technologies, Inc., Portland, Oregon
| | | | - Nicole Vollum
- Pacific Diabetes Technologies, Inc., Portland, Oregon
| | | | - Chad Knutsen
- Pacific Diabetes Technologies, Inc., Portland, Oregon
| | | | | | - Jerry Biehler
- Pacific Diabetes Technologies, Inc., Portland, Oregon
| | | | | | - Jessica R. Castle
- Division of Endocrinology, Diabetes and Nutrition, Oregon Health and Science University, Portland, Oregon
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15
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Pereira AR, Luz RAS, Lima FCDA, Crespilho FN. Protein Oligomerization Based on Brønsted Acid Reaction. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00272] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andressa R. Pereira
- São
Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Paulo, Brazil
| | - Roberto A. S. Luz
- São
Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Paulo, Brazil
| | - Filipe C. D. A. Lima
- Federal Institute of Education, Science and Technology of São Paulo, Campus Matão, 15991-502 São Paulo, Brazil
| | - Frank N. Crespilho
- São
Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Paulo, Brazil
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16
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Halalipour A, Duff MR, Howell EE, Reyes-De-Corcuera JI. Glucose oxidase stabilization against thermal inactivation using high hydrostatic pressure and hydrophobic modification. Biotechnol Bioeng 2016; 114:516-525. [DOI: 10.1002/bit.26185] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/14/2016] [Accepted: 09/13/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Ali Halalipour
- Department of Food Science and Technology; University of Georgia; Food Science Building, 100 Cedar St. Athens, Georgia 30602
| | - Michael R. Duff
- Department of Biochemistry, Cellular and Molecular Biology; University of Tennessee; Knoxville Tennessee
| | - Elizabeth E. Howell
- Department of Biochemistry, Cellular and Molecular Biology; University of Tennessee; Knoxville Tennessee
| | - José I. Reyes-De-Corcuera
- Department of Food Science and Technology; University of Georgia; Food Science Building, 100 Cedar St. Athens, Georgia 30602
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17
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Ritter DW, Newton JM, Roberts JR, McShane MJ. Albuminated Glycoenzymes: Enzyme Stabilization through Orthogonal Attachment of a Single-Layered Protein Shell around a Central Glycoenzyme Core. Bioconjug Chem 2016; 27:1285-92. [PMID: 27111632 DOI: 10.1021/acs.bioconjchem.6b00103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Here we demonstrate an approach to stabilize enzymes through the orthogonal covalent attachment of albumin on the single-enzyme level. Albuminated glycoenzymes (AGs) based upon glucose oxidase and catalase from Aspergillus niger were prepared in this manner. Gel filtration chromatography and dynamic light scattering support modification, with an increase in hydrodynamic radius of ca. 60% upon albumination. Both AGs demonstrate a marked resistance to aggregation during heating to 90 °C, but this effect is more profound in albuminated catalase. The functional characteristics of albuminated glucose oxidase vary considerably with exposure type. The AG's thermal inactivation is reduced more than 25 times compared to native glucose oxidase, and moderate stabilization is observed with one month storage at 37 °C. However, albumination has no effect on operational stability of glucose oxidase.
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Affiliation(s)
- Dustin W Ritter
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843-3120, United States
| | - Jared M Newton
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843-3120, United States
| | - Jason R Roberts
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843-3120, United States
| | - Michael J McShane
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843-3120, United States.,Department of Materials Science & Engineering, Texas A&M University , College Station, Texas 77843-3003, United States
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18
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Thompson JA, Nadeau OW, Carlson GM. A model for activation of the hexadecameric phosphorylase kinase complex deduced from zero-length oxidative crosslinking. Protein Sci 2015; 24:1956-63. [PMID: 26362516 DOI: 10.1002/pro.2804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/04/2015] [Accepted: 09/07/2015] [Indexed: 11/09/2022]
Abstract
Phosphorylase kinase (PhK) is a hexadecameric (αβγδ)(4) enzyme complex that upon activation by phosphorylation stimulates glycogenolysis. Due to its large size (1.3 MDa), elucidating the structural changes associated with the activation of PhK has been challenging, although phosphoactivation has been linked with an increased tendency of the enzyme's regulatory β-subunits to self-associate. Here we report the effect of a peptide mimetic of the phosphoryltable N-termini of β on the selective, zero-length, oxidative crosslinking of these regulatory subunits to form β-β dimers in the nonactivated PhK complex. This peptide stimulated β-β dimer formation when not phosphorylated, but was considerably less effective in its phosphorylated form. Because this peptide mimetic of β competes with its counterpart region in the nonactivated enzyme complex in binding to the catalytic γ-subunit, we were able to formulate a structural model for the phosphoactivation of PhK. In this model, the nonactivated state of PhK is maintained by the interaction between the nonphosphorylated N-termini of β and the regulatory C-terminal domains of the γ-subunits; phosphorylation of β weakens this interaction, leading to activation of the γ-subunits.
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Affiliation(s)
- Jackie A Thompson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas, Kansas, 66160
| | - Owen W Nadeau
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas, Kansas, 66160
| | - Gerald M Carlson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas, Kansas, 66160
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19
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Penketh PG, Shyam K, Baumann RP, Ratner ES, Sartorelli AC. A simple and inexpensive method to control oxygen concentrations within physiological and neoplastic ranges. Anal Biochem 2015; 491:1-3. [PMID: 26361820 DOI: 10.1016/j.ab.2015.08.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/28/2015] [Accepted: 08/31/2015] [Indexed: 11/29/2022]
Abstract
Traditional methods for regulating oxygen concentration ([O2]) in in vitro experiments over the range found in normal and tumor tissues require the use of expensive equipment to generate controlled gas atmospheres or the purchase of a range of gas cylinders with certified O2 percentages. Here we describe a simple and inexpensive enzymatic method for generating low, precise steady-state [O2] levels that are stable for several hours. This method is particularly applicable to the in vitro study of some classes of hypoxia-targeted antitumor prodrugs and bioreductively activated agents.
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Affiliation(s)
- P G Penketh
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - K Shyam
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - R P Baumann
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - E S Ratner
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - A C Sartorelli
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
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20
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Padilla-Martínez SG, Martínez-Jothar L, Sampedro JG, Tristan F, Pérez E. Enhanced thermal stability and pH behavior of glucose oxidase on electrostatic interaction with polyethylenimine. Int J Biol Macromol 2015; 75:453-9. [PMID: 25687477 DOI: 10.1016/j.ijbiomac.2015.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 02/05/2015] [Accepted: 02/06/2015] [Indexed: 12/21/2022]
Abstract
Electrostatic interactions, mediated by ionic-exchange, between polyethylenimine (PEI) and glucose oxidase (GOx) were used to form GOx-PEI macro-complex, which were evaluated for pH and thermal stability of GOx. Under the experimental conditions, the complex had a dominant GOx presence on its surface and a hydrodynamic diameter of 205 ± 16 nm. Activity was evaluated from 40 to 75 °C, and at pH from 2 to 12. GOx activity in complex was maintained up to 70 °C and it was lost at 75 °C. In contrast, free GOx showed a maximum activity at 50 °C, which was completely lost at 70 °C. This difference, observed by fluorescence analysis, was associated with the compact unfolded structure of GOx in the complex. This GOx stability was not observed under pH variations, and complex formation was only possible at pH ≥ 5 where enzymatic activity was diminished by the presence of PEI.
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Affiliation(s)
- Silvia G Padilla-Martínez
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, S.L.P., Mexico
| | - Lucía Martínez-Jothar
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, S.L.P., Mexico
| | - José G Sampedro
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, S.L.P., Mexico
| | - Ferdinando Tristan
- Departamento de Ciencias Naturales - DCNI, Universidad Autónoma Metropolitana Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Cuajimalpa, Santa Fe, 05348 Mexico City, Mexico
| | - Elías Pérez
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, S.L.P., Mexico.
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21
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Jasti LS, Dola SR, Fadnavis NW, Addepally U, Daniels S, Ponrathnam S. Co-immobilized glucose oxidase and β-galactosidase on bovine serum albumin coated allyl glycidyl ether (AGE)–ethylene glycol dimethacrylate (EGDM) copolymer as a biosensor for lactose determination in milk. Enzyme Microb Technol 2014; 64-65:67-73. [DOI: 10.1016/j.enzmictec.2014.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 07/15/2014] [Accepted: 07/15/2014] [Indexed: 12/31/2022]
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22
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Balodite E, Strazdina I, Galinina N, McLean S, Rutkis R, Poole RK, Kalnenieks U. Structure of the Zymomonas mobilis respiratory chain: oxygen affinity of electron transport and the role of cytochrome c peroxidase. MICROBIOLOGY (READING, ENGLAND) 2014; 160:2045-2052. [PMID: 24980645 PMCID: PMC4148688 DOI: 10.1099/mic.0.081612-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Accepted: 06/12/2014] [Indexed: 11/30/2022]
Abstract
The genome of the ethanol-producing bacterium Zymomonas mobilis encodes a bd-type terminal oxidase, cytochrome bc1 complex and several c-type cytochromes, yet lacks sequences homologous to any of the known bacterial cytochrome c oxidase genes. Recently, it was suggested that a putative respiratory cytochrome c peroxidase, receiving electrons from the cytochrome bc1 complex via cytochrome c552, might function as a peroxidase and/or an alternative oxidase. The present study was designed to test this hypothesis, by construction of a cytochrome c peroxidase mutant (Zm6-perC), and comparison of its properties with those of a mutant defective in the cytochrome b subunit of the bc1 complex (Zm6-cytB). Disruption of the cytochrome c peroxidase gene (ZZ60192) caused a decrease of the membrane NADH peroxidase activity, impaired the resistance of growing culture to exogenous hydrogen peroxide and hampered aerobic growth. However, this mutation did not affect the activity or oxygen affinity of the respiratory chain, or the kinetics of cytochrome d reduction. Furthermore, the peroxide resistance and membrane NADH peroxidase activity of strain Zm6-cytB had not decreased, but both the oxygen affinity of electron transport and the kinetics of cytochrome d reduction were affected. It is therefore concluded that the cytochrome c peroxidase does not terminate the cytochrome bc1 branch of Z. mobilis, and that it is functioning as a quinol peroxidase.
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Affiliation(s)
- Elina Balodite
- Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulv. 4, 1586 Riga, Latvia
| | - Inese Strazdina
- Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulv. 4, 1586 Riga, Latvia
| | - Nina Galinina
- Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulv. 4, 1586 Riga, Latvia
| | - Samantha McLean
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Reinis Rutkis
- Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulv. 4, 1586 Riga, Latvia
| | - Robert K. Poole
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Uldis Kalnenieks
- Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulv. 4, 1586 Riga, Latvia
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23
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Akram MS, Ur Rehman J, Hall EAH. Engineered proteins for bioelectrochemistry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2014; 7:257-274. [PMID: 24818813 DOI: 10.1146/annurev-anchem-071213-020143] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
It is only in the past two decades that excellent protein engineering tools have begun to meet parallel advances in materials chemistry, nanofabrication, and electronics. This is revealing scenarios from which synthetic enzymes can emerge, which were previously impossible, as well as interfaces with novel electrode materials. That means the control of the protein structure, electron transport pathway, and electrode surface can usher us into a new era of bioelectrochemistry. This article reviews the principle of electron transfer (ET) and considers how its application at the electrode, within the protein, and at a redox group is directing key advances in the understanding of protein structure to create systems that exhibit better efficiency and unique bioelectrochemistry.
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Affiliation(s)
- Muhammad Safwan Akram
- Institute of Biotechnology, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 1QT United Kingdom;
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24
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Lasave LC, Urteaga R, Koropecki RR, Gonzalez VD, Arce RD. Real-time study of protein adsorption kinetics in porous silicon. Colloids Surf B Biointerfaces 2013; 111:354-9. [PMID: 23856541 DOI: 10.1016/j.colsurfb.2013.06.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 05/11/2013] [Accepted: 06/05/2013] [Indexed: 11/16/2022]
Abstract
This paper presents an optical method for real-time monitoring of protein adsorption using porous silicon self-supported microcavities as a label-free detection platform. The study combines an experimental approach with a physical model for the adsorption process. The proposed model agrees well with experimental observations, and provides information about the kinetics of diffusion and adsorption of proteins within the pores, which will be useful for future experimental designs.
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Affiliation(s)
| | - Raúl Urteaga
- INTEC (UNL-CONICET), Güemes 3450, 3000 Santa Fe, Argentina; Facultad de Ingeniería Química (UNL), Santiago del Estero 2829, 3000 Santa Fe, Argentina
| | - Roberto R Koropecki
- INTEC (UNL-CONICET), Güemes 3450, 3000 Santa Fe, Argentina; Facultad de Ingeniería Química (UNL), Santiago del Estero 2829, 3000 Santa Fe, Argentina
| | | | - Roberto D Arce
- INTEC (UNL-CONICET), Güemes 3450, 3000 Santa Fe, Argentina
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25
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Kagan M, Kivirand K, Rinken T. Modulation of enzyme catalytic properties and biosensor calibration parameters with chlorides: Studies with glucose oxidase. Enzyme Microb Technol 2013; 53:278-82. [DOI: 10.1016/j.enzmictec.2013.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 02/22/2013] [Accepted: 02/25/2013] [Indexed: 11/30/2022]
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26
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Chen B, Qi W, Li X, Lei C, Liu J. Heated proteins are still active in a functionalized nanoporous support. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:2228-2232. [PMID: 23401249 DOI: 10.1002/smll.201202409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 11/27/2012] [Indexed: 06/01/2023]
Abstract
Even under heated conditions, the nearly native conformation and activity of a protein can be hoarded in a functionalized nanoporous support via non-covalent interaction. Surprisingly, the protein released from the heated protein-nanoporous composite can maintain its nearly native conformation and activity, while free proteins are permanently denatured under the same treatment.
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Affiliation(s)
- Baowei Chen
- Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, USA
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27
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Ritter DW, Roberts JR, McShane MJ. Glycosylation site-targeted PEGylation of glucose oxidase retains native enzymatic activity. Enzyme Microb Technol 2013; 52:279-85. [PMID: 23540931 DOI: 10.1016/j.enzmictec.2013.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/04/2013] [Accepted: 01/09/2013] [Indexed: 11/29/2022]
Abstract
Targeted PEGylation of glucose oxidase at its glycosylation sites was investigated to determine the effect on enzymatic activity, as well as the bioconjugate's potential in an optical biosensing assay. Methoxy-poly(ethylene glycol)-hydrazide (4.5kDa) was covalently coupled to periodate-oxidized glycosylation sites of glucose oxidase from Aspergillus niger. The bioconjugate was characterized using gel electrophoresis, liquid chromatography, mass spectrometry, and dynamic light scattering. Gel electrophoresis data showed that the PEGylation protocol resulted in a drastic increase (ca. 100kDa) in the apparent molecular mass of the protein subunit, with complete conversion to the bioconjugate; liquid chromatography data corroborated this large increase in molecular size. Mass spectrometry data proved that the extent of PEGylation was six poly(ethylene glycol) chains per glucose oxidase dimer. Dynamic light scattering data indicated the absence of higher-order oligomers in the PEGylated GOx sample. To assess stability, enzymatic activity assays were performed in triplicate at multiple time points over the course of 29 days in the absence of glucose, as well as before and after exposure to 5% w/v glucose for 24h. At a confidence level of 95%, the bioconjugate's performance was statistically equivalent to native glucose oxidase in terms of activity retention over the 29 day time period, as well as following the 24h glucose exposure. Finally, the bioconjugate was entrapped within a poly(2-hydroxyethyl methacrylate) hydrogel containing an oxygen-sensitive phosphor, and the construct was shown to respond approximately linearly with a 220±73% signal change (n=4, 95% confidence interval) over the physiologically-relevant glucose range (i.e., 0-400mg/dL); to our knowledge, this represents the first demonstration of PEGylated glucose oxidase incorporated into an optical biosensing assay.
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Affiliation(s)
- Dustin W Ritter
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA.
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28
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Vasylieva N, Marinesco S. Enzyme Immobilization on Microelectrode Biosensors. NEUROMETHODS 2013. [DOI: 10.1007/978-1-62703-370-1_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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29
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Bratlie KM, York RL, Invernale MA, Langer R, Anderson DG. Materials for diabetes therapeutics. Adv Healthc Mater 2012; 1:267-84. [PMID: 23184741 PMCID: PMC3899887 DOI: 10.1002/adhm.201200037] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Indexed: 11/10/2022]
Abstract
This review is focused on the materials and methods used to fabricate closed-loop systems for type 1 diabetes therapy. Herein, we give a brief overview of current methods used for patient care and discuss two types of possible treatments and the materials used for these therapies-(i) artificial pancreases, comprised of insulin producing cells embedded in a polymeric biomaterial, and (ii) totally synthetic pancreases formulated by integrating continuous glucose monitors with controlled insulin release through degradable polymers and glucose-responsive polymer systems. Both the artificial and the completely synthetic pancreas have two major design requirements: the device must be both biocompatible and be permeable to small molecules and proteins, such as insulin. Several polymers and fabrication methods of artificial pancreases are discussed: microencapsulation, conformal coatings, and planar sheets. We also review the two components of a completely synthetic pancreas. Several types of glucose sensing systems (including materials used for electrochemical, optical, and chemical sensing platforms) are discussed, in addition to various polymer-based release systems (including ethylene-vinyl acetate, polyanhydrides, and phenylboronic acid containing hydrogels).
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Affiliation(s)
- Kaitlin M. Bratlie
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Roger L. York
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Michael A. Invernale
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Robert Langer
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Harvard-MIT Division of Health Science Technology, Massachusetts Institute of Technology, 45 Carleton Street, Building E25-342, Cambridge, MA 02142, USA
| | - Daniel G. Anderson
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Harvard-MIT Division of Health Science Technology, Massachusetts Institute of Technology, 45 Carleton Street, Building E25-342, Cambridge, MA 02142, USA
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30
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Vasylieva N, Barnych B, Meiller A, Maucler C, Pollegioni L, Lin JS, Barbier D, Marinesco S. Covalent enzyme immobilization by poly(ethylene glycol) diglycidyl ether (PEGDE) for microelectrode biosensor preparation. Biosens Bioelectron 2011; 26:3993-4000. [DOI: 10.1016/j.bios.2011.03.012] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/04/2011] [Accepted: 03/11/2011] [Indexed: 11/26/2022]
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31
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Breaking the barrier to fast electron transfer. Bioelectrochemistry 2009; 76:19-27. [PMID: 19351583 DOI: 10.1016/j.bioelechem.2009.03.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2008] [Revised: 02/25/2009] [Accepted: 03/12/2009] [Indexed: 11/21/2022]
Abstract
A study of the electron transfer for a non-glycosylated redox variant of GOx is reported, immobilised onto an electrode via a polyhistidine tag. The non-glycosylated variant allows the enzyme to be brought closer to the electrode, and within charge transfer distances predicted by Marcus' theory. The enzyme-electrode-hybrid shows direct very fast reversible electrochemical electron transfer, with a rate constant of approximately 350 s(-1) under anaerobic conditions. This is 2 orders of magnitude faster than the enzyme-free flavin adenine dinucleotide (FAD). These results are discussed in the context of the conformation of FAD in the active site of GOx. Further data, presented in the presence of oxygen, show a reduced electron transfer rate (approximately 160 s(-1)) that may be associated with the oxygen interaction with the histidines in the active site. These residues are implicated in the proton transfer mechanism and thus suggest that the presence of oxygen may have a profound effect in attenuating the direct electron transfer rate and thus moderating 'short-circuit' incidental electron transfer between proteins.
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32
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Karaseva EI, Tarun EI, Metelitsa DI. An ultrasonic inactivation of Aspergillus niger glucose oxidase in aqueous solutions. APPL BIOCHEM MICRO+ 2009. [DOI: 10.1134/s0003683809010025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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33
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Ramachandran S, Fontanille P, Pandey A, Larroche C. Permeabilization and inhibition of the germination of spores of Aspergillus niger for gluconic acid production from glucose. BIORESOURCE TECHNOLOGY 2008; 99:4559-65. [PMID: 17889524 DOI: 10.1016/j.biortech.2007.06.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Revised: 05/17/2007] [Accepted: 06/21/2007] [Indexed: 05/17/2023]
Abstract
In this study, the role of citral to permeabilize the spores of Aspergillus niger and replace sodium azide in the bioconversion medium was studied. Further, characterization of glucose oxidase of spores was carried out by exposing both permeabilized and unpermeabilized spores to different pressures (1, 2, 2.7 kb) and temperatures (60, 70, 80, 90 degrees C). Unpermeabilized spores after exposure to high temperatures were permeabilized by freezing before using as catalyst in the bioconversion reaction. Results showed that citral permeabilized the spores and could inhibit spore germination in the bioconversion medium. Rate of reaction was significantly increased from 1.5 to 4.35 g/Lh which was higher than the commercial glucose oxidase 2g/Lh). Glucose oxidase activity of A. niger was resistant to pressure. However, pressure treatment could not permeabilize them. Behaviour of fresh and permeabilized spores to temperature varied significantly. Glucose oxidase activity of fresh spores exposed to high temperature was unaffected at 70 degrees C till 15 min and 84% of relative activity was retained even after 1h at 70 degrees C while permeabilized spore got inactivated at 70 degrees C for 15 min, which followed the same pattern as commercial glucose oxidase. Cellular membrane integrity was lost due to permeabilization by freezing which resulted in heat-inactivation of glucose oxidase when spores were permeabilized before heat treatment. Thus, glucose oxidase of spore remains heat stable when unpermeabilized and active while permeabilized and its reaction rate is higher than the commercial glucose oxidase.
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Affiliation(s)
- Sumitra Ramachandran
- Laboratoire de Génie Chimique et Biochimique, Polytech' Clermont-Ferrand, Université Blaise Pascal, 24, Avenue des Landais, BP 206, F- 63174 Aubière Cedex, France
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34
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Fed-batch Production of Gluconic Acid by Terpene-treated Aspergillus niger Spores. Appl Biochem Biotechnol 2008; 151:413-23. [DOI: 10.1007/s12010-008-8209-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 03/10/2008] [Indexed: 10/22/2022]
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35
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Hatzinikolaou DG, Mamma D, Christakopoulos P, Kekos D. Cell bound and extracellular glucose oxidases from Aspergillus niger BTL: evidence for a secondary glycosylation mechanism. Appl Biochem Biotechnol 2007; 142:29-43. [PMID: 18025566 DOI: 10.1007/s12010-007-0006-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 11/30/1999] [Accepted: 08/18/2006] [Indexed: 12/01/2022]
Abstract
Two glucose oxidase (GOX) isoforms where purified to electrophoretic homogeneity from the mycelium extract (GOXI) and the extracellular medium (GOXII) of Aspergillus niger BTL cultures. Both enzymes were found to be homodimers with nonreduced molecular masses of 148 and 159 kDa and pI values of 3.7 and 3.6 for GOXI and GOXII, respectively. The substrate specificity and the kinetic characteristics of the two GOX forms, as expressed through their apparent K m values on glucose, as well as pH and T activity optima, were almost identical. The only structural difference between the two enzymes was in their degrees of glycosylation, which were determined equal to 14.1 and 20.8% (w/w) of their molecular masses for GOXI and GOXII, respectively. The above difference in the carbohydrate content between the two enzymes seems to influence their pH and thermal stabilities. GOXII proved to be more stable than GOXI at pH values 2.5, 3.0, 8.0, and 9.0. Half-lives of GOXI at pH 3.0 and 8.0 were 8.9 and 17.5 h, respectively, whereas the corresponding values for GOXII were 13.5 and 28.1 h. As far as the thermal stability is concerned, GOXII was also more thermostable than GOXI as judged by the deactivation constants determined at various temperatures. More specifically, the half-lives of GOXI and GOXII, at 45 degrees C, were 12 and 49 h, respectively. These results suggest A. niger BTL probably possesses a secondary glycosylation mechanism that increases the stability of the excreted GOX.
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Affiliation(s)
- Dimitris G Hatzinikolaou
- Laboratory of Microbiology, Department of Botany, School of Biology, National and Kapodistrian University of Athens, Panepistimioupoli Zografou, Athens, Greece
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36
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Liu H, Hu N. Study on Direct Electrochemistry of Glucose Oxidase Stabilized by Cross-Linking and Immobilized in Silica Nanoparticle Films. ELECTROANAL 2007. [DOI: 10.1002/elan.200603792] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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37
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Ehrismann D, Flashman E, Genn D, Mathioudakis N, Hewitson K, Ratcliffe P, Schofield C. Studies on the activity of the hypoxia-inducible-factor hydroxylases using an oxygen consumption assay. Biochem J 2007; 401:227-34. [PMID: 16952279 PMCID: PMC1698668 DOI: 10.1042/bj20061151] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The activity and levels of the metazoan HIF (hypoxia-inducible factor) are regulated by its hydroxylation, catalysed by 2OG (2-oxoglutarate)- and Fe(II)-dependent dioxygenases. An oxygen consumption assay was developed and used to study the relationship between HIF hydroxylase activity and oxygen concentration for recombinant forms of two human HIF hydroxylases, PHD2 (prolyl hydroxylase domain-containing protein 2) and FIH (factor inhibiting HIF), and compared with two other 2OG-dependent dioxygenases. Although there are caveats on the absolute values, the apparent K(m) (oxygen) values for PHD2 and FIH were within the range observed for other 2OG oxygenases. Recombinant protein substrates were found to have lower apparent K(m) (oxygen) values compared with shorter synthetic peptides of HIF. The analyses also suggest that human PHD2 is selective for fragments of the C-terminal over the N-terminal oxygen-dependent degradation domain of HIF-1alpha. The present results, albeit obtained under non-physiological conditions, imply that the apparent K(m) (oxygen) values of the HIF hydroxylases enable them to act as oxygen sensors providing their in vivo capacity is appropriately matched to a hydroxylation-sensitive signalling pathway.
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Affiliation(s)
- Dominic Ehrismann
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Emily Flashman
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - David N. Genn
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Nicolas Mathioudakis
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Kirsty S. Hewitson
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Peter J. Ratcliffe
- †The Henry Wellcome Building for Molecular Physiology, Roosevelt Drive, Oxford OX3 7BN, U.K
- Correspondence may be addressed to either of the authors (email and )
| | - Christopher J. Schofield
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
- Correspondence may be addressed to either of the authors (email and )
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38
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Hassler BL, Worden RM. Versatile bioelectronic interfaces based on heterotrifunctional linking molecules. Biosens Bioelectron 2006; 21:2146-54. [PMID: 16290125 DOI: 10.1016/j.bios.2005.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 10/04/2005] [Accepted: 10/07/2005] [Indexed: 10/25/2022]
Abstract
Bioelectronic interfaces that allow dehydrogenase enzymes to communicate with electrodes have potential applications such as biosensors and biocatalytic reactors. A major challenge in creation of such bioelectronic interfaces is to orient the enzyme, its cofactor, and an electron mediator properly with respect to the electrode in order to achieve efficient, multistep electron transfer. This paper describes a versatile, new method that uses cysteine, an inexpensive, branched amino acid having sulfhydryl, amino, and carboxyl functional groups, to achieve such orientation. This approach provides greater flexibility in assembling complex bioelectronic interfaces than previously reported approaches that bind the enzyme, cofactor, and mediator in a linear chain. Cysteine was attached to a gold electrode through the sulfhydryl groups, to the electron mediator toluidine blue O (TBO) through the carboxyl group, and to the cofactor (e.g., NAD(P)+) through the amino group. Cyclic voltammetry, impedance spectroscopy, chronoamperometry and quartz crystal microbalance gravimetry were used to demonstrate the sequential assembly steps and the electrical activity of the resulting bioelectronic interface.
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Affiliation(s)
- Brian L Hassler
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA
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39
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Otsuka I, Yaoita M, Nagashima S, Higano M. Molecular dimensions of dried glucose oxidase on a Au(111) surface studied by dynamic mode scanning force microscopy. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2005.03.073] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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40
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Zhang S, Wang N, Yu H, Niu Y, Sun C. Covalent attachment of glucose oxidase to an Au electrode modified with gold nanoparticles for use as glucose biosensor. Bioelectrochemistry 2005; 67:15-22. [PMID: 15967397 DOI: 10.1016/j.bioelechem.2004.12.002] [Citation(s) in RCA: 262] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 11/09/2004] [Accepted: 12/14/2004] [Indexed: 11/23/2022]
Abstract
A feasible method to fabricate glucose biosensor was developed by covalent attachment of glucose oxidase (GOx) to a gold nanoparticle monolayer modified Au electrode. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) of ferrocyanide followed and confirmed the assemble process of biosensor, and indicated that the gold nanoparticles in the biosensing interface efficiently improved the electron transfer between analyte and electrode surface. CV performed in the presence of excess glucose and artificial redox mediator, ferrocenemethanol, allowed to quantify the surface concentration of electrically wired enzyme (Gamma(E)(0)) on the basis of kinetic models reported in literature. The Gamma(E)(0) on proposed electrode was high to 4.1 x 10(-12) mol.cm(-2), which was more than four times of that on electrode direct immobilization of enzyme by cystamine without intermediate layer of gold nanoparticles and 2.4 times of a saturated monolayer of GOx on electrode surface. The analytical performance of this biosensor was investigated by amperometry. The sensor provided a linear response to glucose over the concentration range of 2.0 x 10(-5)-5.7 x 10(-3) M with a sensitivity of 8.8 microA.mM(-1).cm(-2) and a detection limit of 8.2 microM. The apparent Michaelis-Menten constant (K(m)(app)) for the sensor was found to be 4.3 mM. In addition, the sensor has good reproducibility, and can remain stable over 30 days.
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Affiliation(s)
- Suxia Zhang
- College of Chemistry, Jilin University, Changchun 130023, PR China
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41
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Arain S, Weiss S, Heinzle E, John GT, Krause C, Klimant I. Gas sensing in microplates with optodes: Influence of oxygen exchange between sample, air, and plate material. Biotechnol Bioeng 2005; 90:271-80. [PMID: 15772950 DOI: 10.1002/bit.20348] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Microplates with integrated optical oxygen sensors are a new tool to study metabolic rates and enzyme activities. Precise measurements are possible only if oxygen exchange between the sample and the environment is known. In this study we quantify gas exchange in plastic microplates. Dissolved oxygen was detected using either an oxygen-sensitive film fixed at the bottom of each well or a needle-type sensor. The diffusion of oxygen into wells sealed with different foils, paraffin oil, and paraffin wax, respectively, was quantified. Although foil covers showed the lowest oxygen permeability, they include an inevitable gas phase between sample and sealing and are difficult to manage. The use of oil was found to be critical due to the extensive shaking caused by movement of the plates during measurements in microplate readers. Thus, paraffin wax was the choice material because it avoids convection of the sample and is easy to handle. Furthermore, without shaking, significant gradients in pO2 levels within a single well of a polystyrene microplate covered with paraffin oil were detected with the needle-type sensor. Higher pO2 levels were obtained near the surface of the sample as well as near the wall of the well. A significant diffusion of oxygen through the plastic plate material was found using plates based on polystyrene. Thus, the location of a sensor element within the well has an effect on the measured pO2 level. Using a sensor film fixed on the bottom of a well or using a dissolved pO2-sensitive indicator results in pO2 offset and in apparently lower respiration rates or enzyme activities. Oxygen diffusion through a polystyrene microplate was simulated for measurements without convection--that is, for samples without oxygen diffusion through the cover and for unshaken measurements using permeable sealings. This mathematical model allows for calculation of the correct kinetic parameters.
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Affiliation(s)
- Sarina Arain
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany
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42
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Mano N, Mao F, Heller A. On the parameters affecting the characteristics of the “wired” glucose oxidase anode. J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2004.08.014] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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43
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Gyurcsányi RE, Jágerszki G, Kiss G, Tóth K. Chemical imaging of biological systems with the scanning electrochemical microscope. Bioelectrochemistry 2004; 63:207-15. [PMID: 15110274 DOI: 10.1016/j.bioelechem.2003.12.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2003] [Revised: 12/09/2003] [Accepted: 12/11/2003] [Indexed: 11/21/2022]
Abstract
A brief overview on recent advances in the application of scanning electrochemical microscopy (SECM) to the investigation of biological systems is presented. Special emphasis is given to the mapping of local enzyme activity by SECM, which is exemplified by relevant original systems.
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Affiliation(s)
- Róbert E Gyurcsányi
- Institute of General and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellért tér 4, Budapest, 1111-Hungary.
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44
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Sharma AL, Singhal R, Kumar A, Rajesh, Pande KK, Malhotra BD. Immobilization of glucose oxidase onto electrochemically prepared poly(aniline-co-fluoroaniline) films. J Appl Polym Sci 2004. [DOI: 10.1002/app.13553] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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45
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Olea D, Faure C. Quantitative study of the encapsulation of glucose oxidase into multilamellar vesicles and its effect on enzyme activity. J Chem Phys 2003. [DOI: 10.1063/1.1601598] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Akhtar MS, Bhakuni V. Alkaline treatment has contrasting effects on the structure of deglycosylated and glycosylated forms of glucose oxidase. Arch Biochem Biophys 2003; 413:221-8. [PMID: 12729620 DOI: 10.1016/s0003-9861(03)00127-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
X-ray crystallographic studies on glucose oxidase showed a strong interaction between carbohydrate and protein moieties of the glycoprotein. However, experimental studies under physiological conditions reported no influence of carbohydrate moiety on the structural and functional properties of glucose oxidase. In order to demonstrate the role of carbohydrate moiety on the structure and stability, we carried out a detailed comparative study on the pH-induced structural changes in the native and deglycosylated forms of glucose oxidase. Our studies demonstrate that at physiological pH both forms of enzyme have very similar structural and stability properties. Acid denaturation also showed similar structural changes in both forms of the enzyme. However, on alkaline treatment contrasting effects on the structure and stability of the two forms of enzyme were observed. The glycosylated enzyme undergoes partial unfolding with decreased stability at alkaline pH; however, a compaction of native conformation and enhanced stability of enzyme was observed for the deglycosylated enzyme under similar conditions. This is the first experimental demonstration of the influence of carbohydrate moiety on structure and stability of glucose oxidase. The studies also indicate the importance of pH studies in evaluating the effect of carbohydrate moiety on the structural and stability properties of glycoprotein.
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Affiliation(s)
- Md Sohail Akhtar
- Division of Molecular and Structural Biology, Central Drug Research Institute, Lucknow 226001, India
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47
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Ito Y, Yamazaki SI, Kano K, Ikeda T. Escherichia coli and its application in a mediated amperometric glucose sensor. Biosens Bioelectron 2002; 17:993-8. [PMID: 12392948 DOI: 10.1016/s0956-5663(02)00091-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Escherichia coli cells, which contain apo-glucose dehydrogenase, were used in constructing a mediated amperometric glucose sensor. The E. coli modified glucose sensor, which was prepared by immobilizing E. coli cells behind a dialysis membrane on a carbon paste electrode containing 2,3-dimethoxy-5-methyl-1,4-benzoquinone (Q(0)), produced a current for the electrocatalytic oxidation of glucose with Q(0) as an electron transfer mediator only after the addition of a trace amount of pyrroloquinoline quinone (PQQ), the cofactor of the enzyme. This allows a novel method of glucose measurements free from the interference of the redox active substances, if contained, in a sample solution. The glucose sensor was insensitive to dioxygen; the currents measured under anaerobic and aerobic conditions, and even under dioxygen saturated conditions were almost the same in magnitude at a given concentration of glucose over the range of 0.2-10 mM. Response time of the glucose sensor was 2 min to attain 90% level of the steady-state current. The E. coli modified glucose sensor was reusable when treated with ethylenediaminetetraacetic acid (EDTA). When E. coli cells were lyophilized, they could be stored at room temperature in a dry box for more than six months without loss of the catalytic activity.
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Affiliation(s)
- Yosuke Ito
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606 8502, Japan
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48
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Haouz A, Glandières JM, Alpert B. Involvement of protein dynamics in enzyme stability. The case of glucose oxidase. FEBS Lett 2001; 506:216-20. [PMID: 11602248 DOI: 10.1016/s0014-5793(01)02917-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Dynamics of glucose oxidase immobilized and in solution were compared through their tryptophan fluorescence spectra, decay times and quenching by acrylamide. Energy barrier for thermal inactivation and melting temperature of both soluble and immobilized enzyme were also measured. Data show that the fluctuation amplitude is at the origin of protein instability.
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Affiliation(s)
- A Haouz
- Laboratoire de Biologie Physico-Chimique, Université Denis Diderot, 2 place Jussieu, 75251 Cedex 05, Paris, France
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49
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Blonder R, Willner I, Bückmann AF. Reconstitution of Apo-Glucose Oxidase on Nitrospiropyran and FAD Mixed Monolayers on Gold Electrodes: Photostimulation of Bioelectrocatalytic Features of the Biocatalyst. J Am Chem Soc 1998. [DOI: 10.1021/ja981126n] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ron Blonder
- Contribution from the Institute of Chemistry and Farkas Center for Light-Induced Processes, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, and Department of Molecular Structure, Gesellschaft für Biotechnologische Forschung, Mascheroder Weg 1, D-38124 Braunschweig, Germany
| | - Itamar Willner
- Contribution from the Institute of Chemistry and Farkas Center for Light-Induced Processes, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, and Department of Molecular Structure, Gesellschaft für Biotechnologische Forschung, Mascheroder Weg 1, D-38124 Braunschweig, Germany
| | - Andreas F. Bückmann
- Contribution from the Institute of Chemistry and Farkas Center for Light-Induced Processes, The Hebrew University of Jerusalem, Jerusalem 91904, Israel, and Department of Molecular Structure, Gesellschaft für Biotechnologische Forschung, Mascheroder Weg 1, D-38124 Braunschweig, Germany
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50
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NAKABAYASHI Y, WAKUDA M, IMAI H. Amperometric Glucose Sensors Fabricated by Electrochemical Polymerization of Phenols on Carbon Paste Electrodes Containing Ferrocene as an Electron Transfer Mediator. ANAL SCI 1998. [DOI: 10.2116/analsci.14.1069] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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