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Hybrid bilayer membranes as platforms for biomimicry and catalysis. Nat Rev Chem 2022; 6:862-880. [PMID: 37117701 DOI: 10.1038/s41570-022-00433-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2022] [Indexed: 11/08/2022]
Abstract
Hybrid bilayer membrane (HBM) platforms represent an emerging nanoscale bio-inspired interface that has broad implications in energy catalysis and smart molecular devices. An HBM contains multiple modular components that include an underlying inorganic surface with a biological layer appended on top. The inorganic interface serves as a support with robust mechanical properties that can also be decorated with functional moieties, sensing units and catalytic active sites. The biological layer contains lipids and membrane-bound entities that facilitate or alter the activity and selectivity of the embedded functional motifs. With their structural complexity and functional flexibility, HBMs have been demonstrated to enhance catalytic turnover frequency and regulate product selectivity of the O2 and CO2 reduction reactions, which have applications in fuel cells and electrolysers. HBMs can also steer the mechanistic pathways of proton-coupled electron transfer (PCET) reactions of quinones and metal complexes by tuning electron and proton delivery rates. Beyond energy catalysis, HBMs have been equipped with enzyme mimics and membrane-bound redox agents to recapitulate natural energy transport chains. With channels and carriers incorporated, HBM sensors can quantify transmembrane events. This Review serves to summarize the major accomplishments achieved using HBMs in the past decade.
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2
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Shulman L, Pei L, Bahnasy MF, Lucy CA. High pH instability of quaternary ammonium surfactant coatings in capillary electrophoresis. Analyst 2018; 142:2145-2151. [PMID: 28524193 DOI: 10.1039/c7an00330g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The two-tailed cationic surfactant dioctadecyldimethyl ammonium bromide (DODAB) produces semi-permanent coatings that yield strongly reversed electroosmotic flow (EOF), for example -0.31 ± 0.01 cm2 kV-1 s-1 at pH 3.5. Moreover, these coatings are easy to prepare, regenerable, cost effective, and yield high efficiency (520 000-900 000 plates per m) separations of cationic proteins over many runs under acidic (pH 3.5) conditions. Given the quaternary amine functionality of DODAB, we were surprised to observe that DODAB coatings become unstable at pH > 7. At pH 7.2, the EOF of a DODAB coated capillary drifted from reversed to cathodic over only 5 runs, and protein separations became severely compromised. By pH 12, no EOF reversal was observed. Electrophoretic and mass spectrometric studies demonstrate that the coating decomposition involves a surface conversion of the quaternary amine in DODAB to a variety of products, although the exact mechanism remains elusive. Regardless, the results herein demonstrate that semi-permanent coatings based on cationic two-tailed surfactants such as DODAB are limited to separations using acidic buffers.
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Affiliation(s)
- Lisa Shulman
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2.
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Kitt JP, Bryce DA, Minteer SD, Harris JM. Confocal Raman Microscopy for in Situ Measurement of Phospholipid-Water Partitioning into Model Phospholipid Bilayers within Individual Chromatographic Particles. Anal Chem 2018; 90:7048-7055. [PMID: 29757613 DOI: 10.1021/acs.analchem.8b01452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The phospholipid-water partition coefficient is a commonly measured parameter that correlates with drug efficacy, small-molecule toxicity, and accumulation of molecules in biological systems in the environment. Despite the utility of this parameter, methods for measuring phospholipid-water partition coefficients are limited. This is due to the difficulty of making quantitative measurements in vesicle membranes or supported phospholipid bilayers, both of which are small-volume phases that challenge the sensitivity of many analytical techniques. In this work, we employ in situ confocal Raman microscopy to probe the partitioning of a model membrane-active compound, 2-(4-isobutylphenyl) propionic acid or ibuprofen, into both hybrid- and supported-phospholipid bilayers deposited on the pore walls of individual chromatographic particles. The large surface-area-to-volume ratio of chromatographic silica allows interrogation of a significant lipid bilayer area within a very small volume. The local phospholipid concentration within a confocal probe volume inside the particle can be as high as 0.5 M, which overcomes the sensitivity limitations of making measurements in the limited membrane areas of single vesicles or planar supported bilayers. Quantitative determination of ibuprofen partitioning is achieved by using the phospholipid acyl-chains of the within-particle bilayer as an internal standard. This approach is tested for measurements of pH-dependent partitioning of ibuprofen into both hybrid-lipid and supported-lipid bilayers within silica particles, and the results are compared with octanol-water partitioning and with partitioning into individual optically trapped phospholipid vesicle membranes. Additionally, the impact of ibuprofen partitioning on bilayer structure is evaluated for both within-particle model membranes and compared with the structural impacts of partitioning into vesicle lipid bilayers.
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Affiliation(s)
- Jay P Kitt
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 United States
| | - David A Bryce
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 United States
| | - Shelley D Minteer
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 United States
| | - Joel M Harris
- Department of Chemistry , University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0850 United States
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Ramos-Payán M, Ocaña-Gonzalez JA, Fernández-Torres RM, Llobera A, Bello-López MÁ. Recent trends in capillary electrophoresis for complex samples analysis: A review. Electrophoresis 2017; 39:111-125. [PMID: 28791719 DOI: 10.1002/elps.201700269] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/17/2017] [Accepted: 07/24/2017] [Indexed: 01/21/2023]
Abstract
CE has been a continuously evolving analytical methodology since its first introduction in the 1980s of the last century. The development of new CE separation procedures, the coupling of these systems to more sensitive and versatile detection systems, and the advances in miniaturization technology have allowed the application of CE to the resolution of new and complex analytical problems, overcoming the traditional disadvantages associated with this method. In the present work, different recent trends in CE and their application to the determination of high complexity samples (as biological fluids, individual cells, etc.) will be reviewed: capillary modification by different types of coatings, microfluidic CE, and online microextraction CE. The main advantages and disadvantages of the different proposed approaches will be discussed with examples of most recent applications.
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Affiliation(s)
- María Ramos-Payán
- Department of Analytical Chemistry, Faculty of Chemistry, University of Seville, Seville, Spain
| | - Juan A Ocaña-Gonzalez
- Department of Analytical Chemistry, Faculty of Chemistry, University of Seville, Seville, Spain
| | | | - Andreu Llobera
- Carl Zeiss Vision GmbH, Technology & Innovation, Aalen, Germany
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Liu Y, Wang W, Jia M, Liu R, Liu Q, Xiao H, Li J, Xue Y, Wang Y, Yan C. Recent advances in microscale separation. Electrophoresis 2017; 39:8-33. [DOI: 10.1002/elps.201700271] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 08/03/2017] [Accepted: 08/04/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Yuanyuan Liu
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Weiwei Wang
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Mengqi Jia
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Rangdong Liu
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Qing Liu
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Han Xiao
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Jing Li
- Unimicro (shanghai) Technologies Co., Ltd.; Shanghai P. R. China
| | - Yun Xue
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Yan Wang
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
| | - Chao Yan
- School of Pharmacy; Shanghai Jiao Tong University; Shanghai P. R. China
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Dawod M, Arvin NE, Kennedy RT. Recent advances in protein analysis by capillary and microchip electrophoresis. Analyst 2017; 142:1847-1866. [PMID: 28470231 PMCID: PMC5516626 DOI: 10.1039/c7an00198c] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This review article describes the significant recent advances in the analysis of proteins by capillary and microchip electrophoresis during the period from mid-2014 to early 2017. This review highlights the progressions, new methodologies, innovative instrumental modifications, and challenges for efficient protein analysis in human specimens, animal tissues, and plant samples. The protein analysis fields covered in this review include analysis of native, reduced, and denatured proteins in addition to Western blotting, protein therapeutics and proteomics.
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Affiliation(s)
- Mohamed Dawod
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, Michigan 48109, USA.
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Wells SS, De La Toba E, Harrison CR. Metal cation control of electroosmotic flow magnitude in phospholipid-coated capillaries. Electrophoresis 2016; 37:1303-9. [PMID: 26960035 DOI: 10.1002/elps.201600012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 11/09/2022]
Abstract
CZE has become widespread for the separation and analysis of biomolecules such as proteins and peptides, due to factors such as, the speed of the separations, low sample volume, and high resolution associated with the technique. However, the separation of biomolecules by CZE does present a significant challenge due to the electrostatic attraction and adsorption of cationic, or cation containing, biomolecules to the capillary surface. To that end numerous methods have been developed to passivate, or protect the surface, in order to prevent the adsorption of analytes. Yet, in the process of protecting the capillary surface, the potential for further modification of the EOF, a factor crucial to effective analyte resolution, is greatly diminished. In seeking to overcome this limitation we have explored the potential of incorporating a range of metal cations into a phospholipid bilayer capillary coating. It has previously been established that the inclusion of calcium into the separation buffer with a phospholipid coating will reverse the EOF in the capillary. Here, we present our investigation of a broader range of metal cations included in the separation buffer (Ca(2+) , Mg(2+) , Co(2+) , Ni(2+) , Sr(2+) , Ba(2+) , and Ce(3+) ) revealing that the choice of metal cation can drastically influence the EOF, with observed values between -3.80 × 10(-4) and -5.74 × 10(-5) cm(2) /V·s.
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Affiliation(s)
- Shane S Wells
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, USA
| | - Eduardo De La Toba
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, USA
| | - Christopher R Harrison
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, USA
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Bright LK, Baker CA, Bränström R, Saavedra SS, Aspinwall CA. Methacrylate Polymer Scaffolding Enhances the Stability of Suspended Lipid Bilayers for Ion Channel Recordings and Biosensor Development. ACS Biomater Sci Eng 2016; 1:955-963. [PMID: 26925461 PMCID: PMC4764998 DOI: 10.1021/acsbiomaterials.5b00205] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Black lipid membranes (BLMs) provide a synthetic environment that facilitates measurement of ion channel activity in diverse analytical platforms. The limited electrical, mechanical and temporal stabilities of BLMs pose a significant challenge to development of highly stable measurement platforms. Here, ethylene glycol dimethacrylate (EGDMA) and butyl methacrylate (BMA) were partitioned into BLMs and photopolymerized to create a cross-linked polymer scaffold in the bilayer lamella that dramatically improved BLM stability. The commercially available methacrylate monomers provide a simple, low cost, and broadly accessible approach for preparing highly stabilized BLMs useful for ion channel analytical platforms. When prepared on silane-modified glass microapertures, the resulting polymer scaffold-stabilized (PSS)-BLMs exhibited significantly improved lifetimes of 23 ± 9 to 40 ± 14 h and > 10-fold increase in mechanical stability, with breakdown potentials > 2000 mV attainable, depending on surface modification and polymer cross-link density. Additionally, the polymer scaffold exerted minimal perturbations to membrane electrical integrity as indicated by mean conductance measurements. When gramicidin A and α-hemolysin were reconstituted into PSS-BLMs, the ion channels retained function comparable to conventional BLMs. This approach is a key advance in the formation of stabilized BLMs and should be amenable to a wide range of receptor and ion channel functionalized platforms.
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Affiliation(s)
- Leonard K. Bright
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
| | - Christopher A. Baker
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
| | - Robert Bränström
- Endocrine and Sarcoma Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - S. Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
- BIO5 Institute, University of Arizona, Tucson, AZ 85721
| | - Craig A. Aspinwall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721
- BIO5 Institute, University of Arizona, Tucson, AZ 85721
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721
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Gallagher ES, Adem SM, Baker CA, Ratnayaka SN, Jones IW, Hall HK, Saavedra SS, Aspinwall CA. Highly stabilized, polymer-lipid membranes prepared on silica microparticles as stationary phases for capillary chromatography. J Chromatogr A 2015; 1385:28-34. [PMID: 25670414 DOI: 10.1016/j.chroma.2015.01.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/14/2015] [Accepted: 01/16/2015] [Indexed: 11/17/2022]
Abstract
The ability to rapidly screen complex libraries of pharmacological modulators is paramount to modern drug discovery efforts. This task is particularly challenging for agents that interact with lipid bilayers or membrane proteins due to the limited chemical, physical, and temporal stability of conventional lipid-based chromatographic stationary phases. Here, we describe the preparation and characterization of a novel stationary phase material composed of highly stable, polymeric-phospholipid bilayers self-assembled onto silica microparticles. Polymer-lipid membranes were prepared by photochemical or redox initiated polymerization of 1,2-bis[10-(2',4'-hexadieoyloxy)decanoyl]-sn-glycero-2-phosphocholine (bis-SorbPC), a synthetic, polymerizable lipid. The resulting polymerized bis-SorbPC (poly(bis-SorbPC)) stationary phases exhibited enhanced stability compared to particles coated with 1,2-dioleoyl-sn-glycero-phosphocholine (unpolymerized) phospholipid bilayers when exposed to chemical (50 mM triton X-100 or 50% acetonitrile) and physical (15 min sonication) insults after 30 days of storage. Further, poly(bis-SorbPC)-coated particles survived slurry packing into fused silica capillaries, compared to unpolymerized lipid membranes, where the lipid bilayer was destroyed during packing. Frontal chromatographic analyses of the lipophilic small molecules acetylsalicylic acid, benzoic acid, and salicylic acid showed >44% increase in retention times (P<0.0001) for all analytes on poly(bis-SorbPC)-functionalized stationary phase compared to bare silica microspheres, suggesting a lipophilic retention mechanism. Phospholipid membrane-functionalized stationary phases that withstand the chemical and physical rigors of capillary LC conditions can substantially increase the efficacy of lipid membrane affinity chromatography, and represents a key advance toward the development of robust membrane protein-functionalized chromatographic stationary phases.
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Affiliation(s)
- Elyssia S Gallagher
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - Seid M Adem
- Department of Chemistry, Washburn University, Topeka, KS 66621, United States
| | - Christopher A Baker
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - Saliya N Ratnayaka
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - Ian W Jones
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - Henry K Hall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - S Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States; Bio5 Institute, University of Arizona, Tucson, AZ 85721, United States
| | - Craig A Aspinwall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States; Bio5 Institute, University of Arizona, Tucson, AZ 85721, United States; Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States.
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