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Dutta P, Roy P, Sengupta N. Effects of External Perturbations on Protein Systems: A Microscopic View. ACS OMEGA 2022; 7:44556-44572. [PMID: 36530249 PMCID: PMC9753117 DOI: 10.1021/acsomega.2c06199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/14/2022] [Indexed: 06/17/2023]
Abstract
Protein folding can be viewed as the origami engineering of biology resulting from the long process of evolution. Even decades after its recognition, research efforts worldwide focus on demystifying molecular factors that underlie protein structure-function relationships; this is particularly relevant in the era of proteopathic disease. A complex co-occurrence of different physicochemical factors such as temperature, pressure, solvent, cosolvent, macromolecular crowding, confinement, and mutations that represent realistic biological environments are known to modulate the folding process and protein stability in unique ways. In the current review, we have contextually summarized the substantial efforts in unveiling individual effects of these perturbative factors, with major attention toward bottom-up approaches. Moreover, we briefly present some of the biotechnological applications of the insights derived from these studies over various applications including pharmaceuticals, biofuels, cryopreservation, and novel materials. Finally, we conclude by summarizing the challenges in studying the combined effects of multifactorial perturbations in protein folding and refer to complementary advances in experiment and computational techniques that lend insights to the emergent challenges.
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Affiliation(s)
- Pallab Dutta
- Department
of Biological Sciences, Indian Institute
of Science Education and Research (IISER) Kolkata, Mohanpur741246, India
| | - Priti Roy
- Department
of Biological Sciences, Indian Institute
of Science Education and Research (IISER) Kolkata, Mohanpur741246, India
- Department
of Chemistry, Oklahoma State University, Stillwater, Oklahoma74078, United States
| | - Neelanjana Sengupta
- Department
of Biological Sciences, Indian Institute
of Science Education and Research (IISER) Kolkata, Mohanpur741246, India
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2
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Stamopoulos D, Bakirtzi N, Manios E, Grapsa E. Does the extracorporeal circulation worsen anemia in hemodialysis patients? Investigation with advanced microscopes of red blood cells drawn at the beginning and end of dialysis. Int J Nanomedicine 2013; 8:3887-94. [PMID: 24143093 PMCID: PMC3798152 DOI: 10.2147/ijn.s49845] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND In hemodialysis (HD) patients, anemia relates to three main factors: insufficient production of erythropoietin; impaired management of iron; and decreased lifespan of red blood cells (RBCs). The third factor can relate to structural deterioration of RBCs due to extrinsic (extracorporeal circuit; biochemical activation and/or mechanical stress during dialysis) and intrinsic (uremic milieu; biochemical interference of the RBC membrane constituents with toxins) mechanisms. Herein, we evaluate information accessed with advanced imaging techniques at the cellular level. METHODS Atomic force and scanning electron microscopes were employed to survey intact RBCs (iRBCs) of seven HD patients in comparison to seven healthy donors. The extrinsic factor was investigated by contrasting pre- and post-HD samples. The intrinsic environment was investigated by comparing the microscopy data with the clinical ones. RESULTS The iRBC membranes of the enrolled HD patients were overpopulated with orifice-like (high incidence; typical size within 100-1,000 nm) and crevice-like (low incidence; typical size within 500-4,000 nm) defects that exhibited a statistically significant (P < 0.05) relative increase (+55% and +350%, respectively) in respect to healthy donors. The relative variation of the orifice and crevice indices (mean population of orifices and crevices per top membrane surface) between pre- and post-HD was not statistically significant (-3.3% and +4.5%, respectively). The orifice index correlates with the concentrations of urea, calcium, and phosphorus, but not, however, with that of creatinine. CONCLUSION Extracorporeal circulation is not detrimental to the structural integrity of RBC membranes. Uremic milieu is a candidate cause of RBC membrane deterioration, which possibly worsens anemia.
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Affiliation(s)
- Dimosthenis Stamopoulos
- Institute of Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, National Center for Scientific Research 'Demokritos,' Athens, Greece
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3
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Stamopoulos D, Grapsa E, Manios E, Gogola V, Bakirtzi N. Defected red blood cell membranes and direct correlation with the uraemic milieu: the connection with the decreased red blood cell lifespan observed in haemodialysis patients. NANOTECHNOLOGY 2012; 23:485101. [PMID: 23124094 DOI: 10.1088/0957-4484/23/48/485101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Together with impaired production of erythropoietin and iron deficiency, the decreased lifespan of red blood cells (RBCs) is a main factor contributing to the chronic anaemia observed in haemodialysis (HD) patients. Atomic force microscopy is employed in this work to thoroughly survey the membrane of intact RBCs (iRBCs) of HD patients in comparison to those of healthy donors, aiming to obtain direct information on the structural status of RBCs that can be related to their decreased lifespan. We observed that the iRBC membrane of the HD patients is overpopulated with extended circular defects, termed 'orifices', that have typical dimension ranging between 0.2 and 1.0 μm. The 'orifice' index-that is, the mean population of 'orifices' per top membrane surface-exhibits a pronounced relative increase of order 54 ± 12% for the HD patients as compared to healthy donors. Interestingly, for the HD patients, the 'orifice' index, which relates to the structural status of the RBC membrane, correlates strongly with urea concentration, which is a basic index of the uraemic milieu. Thus, these results indicate that the uraemic milieu downgrades the structural status of the RBC membrane, possibly triggering biochemical processes that result in their premature elimination from the circulation. This process could decrease the lifespan of RBCs, as observed in HD patients.
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Affiliation(s)
- D Stamopoulos
- Institute of Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, National Centre for Scientific Research-Demokritos, Agia Paraskevi, Greece.
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4
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Yoon JH, Lee KS, Yang J, Won MS, Shim YB. Electron transfer kinetics and morphology of cytochrome c at the biomimetic phospholipid layers. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2010.03.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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5
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Lin WC, Blanchette CD, Ratto TV, Longo ML. Lipid domains in supported lipid bilayer for atomic force microscopy. Methods Mol Biol 2007; 400:503-13. [PMID: 17951756 DOI: 10.1007/978-1-59745-519-0_34] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Phase-separated supported lipid bilayers have been widely used to study the phase behavior of multicomponent lipid mixtures. One of the primary advantages of using supported lipid bilayers is that the two-dimensional platform of this model membrane system readily allows lipid-phase separation to be characterized by high-resolution imaging techniques such as atomic force microscopy (AFM). In addition, when supported lipid bilayers have been functionalized with a specific ligand, protein-membrane interactions can also be imaged and characterized through AFM. It has been recently demonstrated that when the technique of vesicle fusion is used to prepare supported lipid bilayers, the thermal history of the vesicles before deposition and the supported lipid bilayers after formation will have significant effects on the final phase-separated domain structures. In this chapter, three methods of vesicle preparations as well as three deposition conditions will be presented. Also, the techniques and strategies of using AFM to image multicomponent phase-separated supported lipid bilayers and protein binding will be discussed.
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Affiliation(s)
- Wan-Chen Lin
- Division of Biological Sciences, University of California, Davis, USA
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6
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Yoder NC, Kalsani V, Schuy S, Vogel R, Janshoff A, Kumar K. Nanoscale patterning in mixed fluorocarbon-hydrocarbon phospholipid bilayers. J Am Chem Soc 2007; 129:9037-43. [PMID: 17602478 PMCID: PMC2507729 DOI: 10.1021/ja070950l] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A growing body of literature suggests that fluorocarbons can direct self-assembly within hydrocarbon environments. We report here the fabrication and characterization of supported lipid bilayers (SLBs) composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and a synthetic, fluorocarbon-functionalized analogue, 1. AFM investigation of these model membranes reveals an intricate, composition-dependent domain structure consisting of approximately 50 nm stripes interspersed between approximately 1 microm sized domains. Although DSC of 1 showed a phase transition near room temperature, DSC of DPPC:1 mixtures exhibited complex phase behavior suggesting domain segregation. Finally, temperature-dependent AFM of DPPC:1 bilayers shows that, while the stripe structures can be melted above the Tm of 1, the stripes and domains result from immiscibility of the hydrocarbon and fluorocarbon lipid gel phases. Fluorination appears to be a promising strategy for chemical self-assembly in two dimensions. In particular, because no modification is made to the lipid headgroups, it may be useful for nanopatterning biologically relevant ligands on bilayers in vitro or in living cells.
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Affiliation(s)
| | | | - Steffen Schuy
- Institute for Physical Chemistry, University of Mainz, 55128 Mainz, Germany
| | - Reiner Vogel
- Institute for Molecular Medicine and Cell Research, University of Freiburg, 79104 Freiburg, Germany
| | - Andreas Janshoff
- Institute for Physical Chemistry, University of Mainz, 55128 Mainz, Germany
| | - Krishna Kumar
- Department of Chemistry, Tufts University, Medford MA 02155
- Cancer Center, Tufts-New England Medical Center, Boston MA 02110
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7
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Dwiecki K, Górnas P, Wilk A, Nogala-Kałucka M, Polewski K. Spectroscopic studies of D-alpha-tocopherol concentration-induced transformation in egg phosphatidylcholine vesicles. Cell Mol Biol Lett 2006; 12:51-69. [PMID: 17124545 PMCID: PMC6275860 DOI: 10.2478/s11658-006-0059-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 08/09/2006] [Indexed: 12/05/2022] Open
Abstract
The effects of embedding up to 60 mol% of α-tocopherol (α-Toc) on the morphology and structure of the egg phosphatidylcholine (PC) membrane were studied using spectroscopic techniques. The resulting vesicles were subjected to turbidometric and dynamic light scattering measurements to evaluate their size distribution. The α-Toc intrinsic fluorescence and its quenching was used to estimate the tocopherol position in the membrane. Optical microscopy was used to visualize morphological changes in the vesicles during the inclusion of tocopherol into the 2 mg/ml PC membrane. The incorporation of up to 15 mol% of tocopherol molecules into PC vesicles is accompanied by a linear increase in the fluorescence intensity and the simultaneous formation of larger, multilamellar vesicles. Increasing the tocopherol concentration above 20 mol% induced structural and morphological changes leading to the disappearance of micrometer-sized vesicles and the formation of small unilamellar vesicles of size ranging from 30 to 120 nm, mixed micelles and non-lamellar structures.
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8
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Sonnino S, Prinetti A, Mauri L, Chigorno V, Tettamanti G. Dynamic and Structural Properties of Sphingolipids as Driving Forces for the Formation of Membrane Domains. Chem Rev 2006; 106:2111-25. [PMID: 16771445 DOI: 10.1021/cr0100446] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sandro Sonnino
- Center of Excellence on Neurodegenerative Diseases, Department of Medical Chemistry, Biochemistry and Biotechnology, University of Milan, 20090 Segrate (MI), Italy.
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9
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Chapter 4 Visualization and Characterization of Domains in Supported Model Membranes. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s1554-4516(05)03004-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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10
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Jensen MØ, Mouritsen OG. Lipids do influence protein function-the hydrophobic matching hypothesis revisited. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1666:205-26. [PMID: 15519316 DOI: 10.1016/j.bbamem.2004.06.009] [Citation(s) in RCA: 308] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Revised: 05/28/2004] [Accepted: 06/24/2004] [Indexed: 11/27/2022]
Abstract
A topical review of the current state of lipid-protein interactions is given with focus on the physical interactions between lipids and integral proteins in lipid-bilayer membranes. The concepts of hydrophobic matching and curvature stress are revisited in light of recent data obtained from experimental and theoretical studies which demonstrate that not only do integral proteins perturb the lipids, but the physical state of the lipids does also actively influence protein function. The case of the trans-membrane water-channel protein aquaporin GlpF from E. coli imbedded in lipid-bilayer membranes is discussed in some detail. Numerical data obtained from Molecular Dynamics simulations show on the one side that the lipid bilayer adapts to the channel by a hydrophobic matching condition which reflects the propensity of the lipid molecules for forming curved structures. On the other side, it is demonstrated that the transport function of the channel is modulated by the matching condition and/or the curvature stress in a lipid-specific manner.
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Affiliation(s)
- Morten Ø Jensen
- MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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11
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SHIMOSAKA T, NAKAMURA K, UCHIYAMA K, HOBO T. Fluctuation of Thermal Lens Signal in Total Internal Reflection Configuration from Phospholipid Bilayer. BUNSEKI KAGAKU 2005. [DOI: 10.2116/bunsekikagaku.54.549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takuya SHIMOSAKA
- Tokyo Metropolitan University, School of Engineering
- National Institute of Advanced Industrial Science and Technology, National Metrology Institute of Japan
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12
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Karlsson M, Davidson M, Karlsson R, Karlsson A, Bergenholtz J, Konkoli Z, Jesorka A, Lobovkina T, Hurtig J, Voinova M, Orwar O. BIOMIMETIC NANOSCALE REACTORS AND NETWORKS. Annu Rev Phys Chem 2004; 55:613-49. [PMID: 15117264 DOI: 10.1146/annurev.physchem.55.091602.094319] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Methods based on self-assembly, self-organization, and forced shape transformations to form synthetic or semisynthetic enclosed lipid bilayer structures with several properties similar to biological nanocompartments are reviewed. The procedures offer unconventional micro- and nanofabrication routes to yield complex soft-matter devices for a variety of applications for example, in physical chemistry and nanotechnology. In particular, we describe novel micromanipulation methods for producing fluid-state lipid bilayer networks of nanotubes and surface-immobilized vesicles with controlled geometry, topology, membrane composition, and interior contents. Mass transport in nanotubes and materials exchange, for example, between conjugated containers, can be controlled by creating a surface tension gradient that gives rise to a moving boundary or by induced shape transformations. The network devices can operate with extremely small volume elements and low mass, to the limit of single molecules and particles at a length scale where a continuum mechanics approximation may break down. Thus, we also describe some concepts of anomalous fluctuation-dominated kinetics and anomalous diffusive behaviours, including hindered transport, as they might become important in studying chemistry and transport phenomena in these confined systems. The networks are suitable for initiating and controlling chemical reactions in confined biomimetic compartments for rationalizing, for example, enzyme behaviors, as well as for applications in nanofluidics, bioanalytical devices, and to construct computational and complex sensor systems with operations building on chemical kinetics, coupled reactions and controlled mass transport.
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Affiliation(s)
- Mattias Karlsson
- Department of Chemistry and Bioscience, and Microtechnology Center at Chalmers, SE-41296 Goteborg, Sweden
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13
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NAKAMURA K, SHIMOSAKA T, UCHIYAMA K, HOBO T. Observation of a metal cation entering into a phospholipid bilayer by total internal reflection with thermal lens spectroscopy. BUNSEKI KAGAKU 2004. [DOI: 10.2116/bunsekikagaku.53.1067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Kaori NAKAMURA
- Graduate School of Engineering, Tokyo Metropolitan University
| | - Takuya SHIMOSAKA
- Graduate School of Engineering, Tokyo Metropolitan University
- Present Address, Organic Analytical Division, National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST)
| | | | - Toshiyuki HOBO
- Graduate School of Engineering, Tokyo Metropolitan University
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14
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Cohen Simonsen A, Bernchou Jensen U, Faergeman NJ, Knudsen J, Mouritsen OG. Acyl-coenzyme A organizes laterally in membranes and is recognized specifically by acyl-coenzyme A binding protein. FEBS Lett 2003; 552:253-8. [PMID: 14527695 DOI: 10.1016/s0014-5793(03)00970-0] [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: 11/30/2022]
Abstract
Long chain acyl-coenzyme A (acyl-CoA) is a biochemically important amphiphilic molecule that is known to partition strongly into membranes by insertion of the acyl chain. At present, microscopically resolved evidence is lacking on how acyl-CoA influences and organizes laterally in membranes. By atomic force microscopy (AFM) imaging of membranes exposed to acyl-CoA in microM concentrations, it is shown that aggregate formation takes place within the membrane upon long-time exposure. It is known that acyl-CoA is bound by acyl-CoA binding protein (ACBP) with high affinity and specificity and that ACBP may bind and desorb membrane-bound acyl-CoA via a partly unknown mechanism. Following incubation with acyl-CoA, it is shown that ACBP is able to reverse the formation of acyl-CoA aggregates and to associate peripherally with acyl-CoA on the membrane surface. Our microscopic results point to the role of ACBP as an intermembrane transporter of acyl-CoA and demonstrate the ability of AFM to reveal the remodelling of membranes by surfactants and proteins.
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Affiliation(s)
- A Cohen Simonsen
- MEMPHYS, Physics Department, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
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15
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Effects of carbon chain difference and lipid composition on the contact mechanics of two-component vesicle. Colloids Surf B Biointerfaces 2003. [DOI: 10.1016/s0927-7765(03)00126-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Zieziulewicz TJ, Unfricht DW, Hadjout N, Lynes MA, Lawrence DA. Shrinking the biologic world--nanobiotechnologies for toxicology. Toxicol Sci 2003; 74:235-44. [PMID: 12832654 DOI: 10.1093/toxsci/kfg108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Although toxicologic effects need to be considered at the organismal level, the adverse events originate from interactions and alterations at the molecular level. Cellular structures and functions can be disrupted by modifications of the nanometer structure of critical molecules; therefore, devices used to assess biologic and toxicologic processes at the nanoscale will allow important new research pursuits. In order to properly assess alterations at these dimensions, nanofabricated tools are needed to detect, separate, analyze, and manipulate cells or biologic molecules of interest. The emergence of laser tweezers, surface plasmon resonance (SPR), laser capture microdissection (LCM), atomic force microscopy (AFM), and multi-photon microscopes have allowed for these assessments. Micro- and nanobiotechnologies will further advance biologic, clinical, and toxicologic endeavors with the aid of miniaturized, more sensitive devices. Miniaturized table-top laboratory equipment incorporating additional innovative technologies can lead to new advances, including micro total analysis systems (microTAS) or "lab-on-a-chip" and "sentinel sensor" devices. This review will highlight several devices, which have been made possible by techniques originating in the microelectronics industry. These devices can be used for toxicologic assessment of cellular structures and functions, such as cellular adhesion, signal transduction, motility, deformability, metabolism, and secretion.
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Affiliation(s)
- Thomas J Zieziulewicz
- Laboratory of Clinical and Experimental Endocrinology and Immunology, Wadsworth Center, New York State Department of Health, Albany, New York 12201, USA
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17
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Tokumasu F, Jin AJ, Feigenson GW, Dvorak JA. Nanoscopic lipid domain dynamics revealed by atomic force microscopy. Biophys J 2003; 84:2609-18. [PMID: 12668469 PMCID: PMC1302827 DOI: 10.1016/s0006-3495(03)75066-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intrinsic heterogeneities, represented as domain formations in biological membranes, are important to both the structure and function of the membranes. We observed domain formations in mixed lipid bilayers of dipalmitoylphosphatidylcholine (DPPC), dilauroylphosphatidylcholine (DLPC), and cholesterol (chol) in a fluid environment using an atomic force microscope (AFM). At room temperature, we demonstrated that both microscopic and nanoscopic domains coexist and the DPPC-rich domain is approximately 1.4 nm higher than the surrounding DLPC-rich membrane areas as a consequence of intrinsic phase differences. DPPC-rich microscopic domains became larger as DPPC concentration increased. In cholesterol-free mixtures, nanoscopic DPPC-rich domain sizes ranged from 26 to 46 nm depending on phospholipid concentration. Domain size varied between 33 and 48 nm in the presence of cholesterol (0 < or = [chol] < or = 40). The nanoscopic domains were markedly fragmented near [chol] = 0.135 and appeared to fuse more readily into microscopic domains at higher and lower [chol]. By phase balance analyses we demonstrated phase behavior differences between a free-vesicle GUV system studied by confocal light microscopy and a supported membrane system studied by AFM. We propose a new three-dimensional phase diagram elucidating the effects of a solid substrate support on lipid phase behavior relevant to complex membrane phase phenomena in biological systems.
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Affiliation(s)
- Fuyuki Tokumasu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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18
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Jørgensen K, Davidsen J, Mouritsen OG. Biophysical mechanisms of phospholipase A2 activation and their use in liposome-based drug delivery. FEBS Lett 2002; 531:23-7. [PMID: 12401197 DOI: 10.1016/s0014-5793(02)03408-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Secretory phospholipase A2 (PLA2) is a ubiquitous water-soluble enzyme found in venom, pancreatic, and cancerous fluid. It is also known to play a role in membrane remodeling processes as well as in cellular signaling cascades. PLA2 is interfacially active and functions mainly on organized types of substrate, e.g. micelles and lipid bilayers. Hence the activity of the enzyme is modulated by the lateral organization and the physical properties of the substrate, in particular the structure in the nanometer range. The evidence for nano-scale structure and lipid domains in bilayers is briefly reviewed. Results obtained from a variety of experimental and theoretical studies of PLA2 activity on lipid-bilayer substrates are then presented which provide insight into the biophysical mechanisms of PLA2 activation on lipid bilayers and liposomes of different composition. The insight into these mechanisms has been used to propose a novel principle for liposomal drug targeting, release, and absorption triggered by secretory PLA2.
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Affiliation(s)
- Kent Jørgensen
- MEMPHYS - Center for Biomembrane Physics, LiPlasome Pharma A/S, Technical University of Denmark, Building 207, DK-2800, Lyngby, Denmark
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