1
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Hristova SH, Zhivkov AM. Intermolecular Electrostatic Interactions in Cytochrome c Protein Monolayer on Montmorillonite Alumosilicate Surface: A Positive Cooperative Effect. Int J Mol Sci 2024; 25:6834. [PMID: 38999945 PMCID: PMC11241403 DOI: 10.3390/ijms25136834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 07/14/2024] Open
Abstract
Montmorillonite (MM) crystal nanoplates acquire anticancer properties when coated with the mitochondrial protein cytochrome c (cytC) due to the cancer cells' capability to phagocytize cytC-MM colloid particles. The introduced exogenous cytC initiates apoptosis: an irreversible cascade of biochemical reactions leading to cell death. In the present research, we investigate the organization of the cytC layer on the MM surface by employing physicochemical and computer methods-microelectrophoresis, static, and electric light scattering-to study cytC adsorption on the MM surface, and protein electrostatics and docking to calculate the local electric potential and Gibbs free energy of interacting protein globules. The found protein concentration dependence of the adsorbed cytC quantity is nonlinear, manifesting a positive cooperative effect that emerges when the adsorbed cytC globules occupy more than one-third of the MM surface. Computer analysis reveals that the cooperative effect is caused by the formation of protein associates in which the cytC globules are oriented with oppositely charged surfaces. The formation of dimers and trimers is accompanied by a strong reduction in the electrostatic component of the Gibbs free energy of protein association, while the van der Waals component plays a secondary role.
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Affiliation(s)
- Svetlana H Hristova
- Department of Medical Physics and Biophysics, Medical Faculty, Medical University-Sofia, Zdrave Str. 2, 1431 Sofia, Bulgaria
| | - Alexandar M Zhivkov
- Scientific Research Center, "St. Kliment Ohridski" Sofia University, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria
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2
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Frenzel J, Kupferer A, Zink M, Mayr SG. Laminin Adsorption and Adhesion of Neurons and Glial Cells on Carbon Implanted Titania Nanotube Scaffolds for Neural Implant Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3858. [PMID: 36364633 PMCID: PMC9656521 DOI: 10.3390/nano12213858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/17/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Interfacing neurons persistently to conductive matter constitutes one of the key challenges when designing brain-machine interfaces such as neuroelectrodes or retinal implants. Novel materials approaches that prevent occurrence of loss of long-term adhesion, rejection reactions, and glial scarring are highly desirable. Ion doped titania nanotube scaffolds are a promising material to fulfill all these requirements while revealing sufficient electrical conductivity, and are scrutinized in the present study regarding their neuron-material interface. Adsorption of laminin, an essential extracellular matrix protein of the brain, is comprehensively analyzed. The implantation-dependent decline in laminin adsorption is revealed by employing surface characteristics such as nanotube diameter, ζ-potential, and surface free energy. Moreover, the viability of U87-MG glial cells and SH-SY5Y neurons after one and four days are investigated, as well as the material's cytotoxicity. The higher conductivity related to carbon implantation does not affect the viability of neurons, although it impedes glial cell proliferation. This gives rise to novel titania nanotube based implant materials with long-term stability, and could reduce undesirable glial scarring.
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Affiliation(s)
- Jan Frenzel
- Leibniz Institute of Surface Engineering (IOM), 04318 Leipzig, Germany
- Division of Surface Physics, Faculty of Physics and Earth Sciences, Leipzig University, 04103 Leipzig, Germany
- Research Group Biotechnology and Biomedicine, Faculty of Physics and Earth Sciences, Leipzig University, 04103 Leipzig, Germany
| | - Astrid Kupferer
- Leibniz Institute of Surface Engineering (IOM), 04318 Leipzig, Germany
- Division of Surface Physics, Faculty of Physics and Earth Sciences, Leipzig University, 04103 Leipzig, Germany
| | - Mareike Zink
- Research Group Biotechnology and Biomedicine, Faculty of Physics and Earth Sciences, Leipzig University, 04103 Leipzig, Germany
| | - Stefan G. Mayr
- Leibniz Institute of Surface Engineering (IOM), 04318 Leipzig, Germany
- Division of Surface Physics, Faculty of Physics and Earth Sciences, Leipzig University, 04103 Leipzig, Germany
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3
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Bildanau E, Vikhrenko V. Adsorption time scales of cluster-forming systems. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2021; 44:51. [PMID: 33844108 DOI: 10.1140/epje/s10189-021-00059-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
A microscopic model of adsorption in cluster forming systems with competing interaction is considered. The adsorption process is described by the master equation and modelled by a kinetic Monte Carlo method. The evolution of the particle concentration and interaction energy during the adsorption of particles on a plane triangular lattice is investigated. The simulation results show a diverse behavior of the system time evolution depending on the temperature and chemical potential and finally on the formation of clusters in the system. The characteristic relaxation times of adsorption vary in several orders of magnitude depending on the thermodynamic parameters of the final equilibrium state of the adsorbate. A very fast adsorption of particles is observed for highly ordered adsorbate equilibrium states.
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Affiliation(s)
- Eldar Bildanau
- Belarusian State Technological University, 220006, Minsk, Belarus.
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4
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Mulheran PA, Connell DJ, Kubiak-Ossowska K. Steering protein adsorption at charged surfaces: electric fields and ionic screening. RSC Adv 2016. [DOI: 10.1039/c6ra16391b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Protein adsorption at charged surfaces is a common process in the development of functional technological devices.
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Affiliation(s)
- Paul A. Mulheran
- Department of Chemical and Process Engineering
- University of Strathclyde
- Glasgow G1 1XJ
- UK
| | - David J. Connell
- Department of Chemical and Process Engineering
- University of Strathclyde
- Glasgow G1 1XJ
- UK
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5
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Kubiak-Ossowska K, Cwieka M, Kaczynska A, Jachimska B, Mulheran PA. Lysozyme adsorption at a silica surface using simulation and experiment: effects of pH on protein layer structure. Phys Chem Chem Phys 2015; 17:24070-7. [PMID: 26315945 DOI: 10.1039/c5cp03910j] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hen Egg White Lysozyme (HEWL) is a widely used exemplar to study protein adsorption on surfaces and interfaces. Here we use fully atomistic Molecular Dynamics (MD) simulations, Multi-Parametric Surface Plasmon Resonance (MP-SPR), contact angle and zeta potential measurements to study HEWL adsorption at a silica surface. The simulations provide a detailed description of the adsorption mechanism and indicate that at pH7 the main adsorption driving force is electrostatics, supplemented by weaker hydrophobic forces. Moreover, they reveal the preferred orientation of the adsorbed protein and show that its structure is only slightly altered at the interface with the surface. This provides the basis for interpreting the experimental results, which indicate the surface adsorbs a close-packed monolayer at about pH10 where the surface has a large negative zeta potential and the HEWL is positively charged. At higher pH, the adsorption amount of the protein layer is greatly reduced due to the loss of charge on the protein. At lower pH, the smaller zeta potential of the surface leads to lower HEWL adsorption. These interpretations are complemented by the contact angle measurements that show how the hydrophobicity of the surface is greatest when the surface coverage is highest. The simulations provide details of the hydrophobic residues exposed to solution by the adsorbed HEWL, completing the picture of the protein layer structure.
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Affiliation(s)
- Karina Kubiak-Ossowska
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, UK.
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6
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Kastantin M, Langdon BB, Schwartz DK. A bottom-up approach to understanding protein layer formation at solid-liquid interfaces. Adv Colloid Interface Sci 2014; 207:240-52. [PMID: 24484895 PMCID: PMC4028386 DOI: 10.1016/j.cis.2013.12.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 12/05/2013] [Accepted: 12/17/2013] [Indexed: 11/25/2022]
Abstract
A common goal across different fields (e.g. separations, biosensors, biomaterials, pharmaceuticals) is to understand how protein behavior at solid-liquid interfaces is affected by environmental conditions. Temperature, pH, ionic strength, and the chemical and physical properties of the solid surface, among many factors, can control microscopic protein dynamics (e.g. adsorption, desorption, diffusion, aggregation) that contribute to macroscopic properties like time-dependent total protein surface coverage and protein structure. These relationships are typically studied through a top-down approach in which macroscopic observations are explained using analytical models that are based upon reasonable, but not universally true, simplifying assumptions about microscopic protein dynamics. Conclusions connecting microscopic dynamics to environmental factors can be heavily biased by potentially incorrect assumptions. In contrast, more complicated models avoid several of the common assumptions but require many parameters that have overlapping effects on predictions of macroscopic, average protein properties. Consequently, these models are poorly suited for the top-down approach. Because the sophistication incorporated into these models may ultimately prove essential to understanding interfacial protein behavior, this article proposes a bottom-up approach in which direct observations of microscopic protein dynamics specify parameters in complicated models, which then generate macroscopic predictions to compare with experiment. In this framework, single-molecule tracking has proven capable of making direct measurements of microscopic protein dynamics, but must be complemented by modeling to combine and extrapolate many independent microscopic observations to the macro-scale. The bottom-up approach is expected to better connect environmental factors to macroscopic protein behavior, thereby guiding rational choices that promote desirable protein behaviors.
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Affiliation(s)
- Mark Kastantin
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, United States
| | - Blake B Langdon
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, United States.
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7
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Langdon BB, Kastantin M, Walder R, Schwartz DK. Interfacial protein-protein associations. Biomacromolecules 2013; 15:66-74. [PMID: 24274729 DOI: 10.1021/bm401302v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
While traditional models of protein adsorption focus primarily on direct protein-surface interactions, recent findings suggest that protein-protein interactions may play a central role. Using high-throughput intermolecular resonance energy transfer (RET) tracking, we directly observed dynamic, protein-protein associations of bovine serum albumin on polyethylene glycol modified surfaces. The associations were heterogeneous and reversible, and associating molecules resided on the surface for longer times. The appearance of three distinct RET states suggested a spatially heterogeneous surface - with areas of high protein density (i.e., strongly interacting clusters) coexisting with mobile monomers. Distinct association states exhibited characteristic behavior, i.e., partial-RET (monomer-monomer) associations were shorter-lived than complete-RET (protein-cluster) associations. While the fractional surface area covered by regions with high protein density (i.e., clusters) increased with increasing concentration, the distribution of contact times between monomers and clusters was independent of solution concentration, suggesting that associations were a local phenomenon, and independent of the global surface coverage.
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Affiliation(s)
- Blake B Langdon
- Department of Chemical and Biological Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States
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8
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Saha B, Saikia J, Das G. Tuning the selective interaction of lysozyme and serum albumin on a carboxylate modified surface. RSC Adv 2013. [DOI: 10.1039/c3ra23042b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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9
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Xu K, Ouberai MM, Welland ME. A comprehensive study of lysozyme adsorption using dual polarization interferometry and quartz crystal microbalance with dissipation. Biomaterials 2012. [PMID: 23195491 DOI: 10.1016/j.biomaterials.2012.10.078] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein adsorption plays a crucial role in biomaterial surface science as it is directly linked to the biocompatibility of artificial biomaterial devices. Here, elucidation of protein adsorption mechanism is effected using dual polarization interferometry and a quartz crystal microbalance to characterize lysozyme layer properties on a silica surface at different coverage values. Lysozyme is observed to adsorb from sparse monolayer to multilayer coverage. At low coverage an irreversibly adsorbed layer is formed with slight deformation consistent with side-on orientation. At higher coverage values dynamic re-orientation effects are observed which lead to monolayer surface coverages of 2-3 ng/mm² corresponding to edge-on or/and end-on orientations. These monolayer thickness values ranged between 3 and 4.5 nm with a protein density value of 0.60 g/mL and with 50 wt% solvent mass. Further increase of coverage results formation of a multilayer structure. Using the hydration content and other physical layer properties a tentative model lysozyme adsorption is proposed.
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Affiliation(s)
- Kairuo Xu
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB3 0FF, UK
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10
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Kubiak-Ossowska K, Mulheran PA. Protein diffusion and long-term adsorption states at charged solid surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15577-15585. [PMID: 23062108 DOI: 10.1021/la303323r] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The diffusion pathways of lysozyme adsorbed to a model charged ionic surface are studied using fully atomistic steered molecular dynamics simulation. The simulations start from existing protein adsorption trajectories, where it has been found that one particular residue, Arg128 at the N,C-terminal face, plays a crucial role in anchoring the lysozyme to the surface [Langmuir 2010 , 26 , 15954 - 15965]. We first investigate the desorption pathway for the protein by pulling the Arg128 side chain away from the surface in the normal direction, and its subsequent readsorption, before studying diffusion pathways by pulling the Arg128 side chain parallel to the surface. We find that the orientation of this side chain plays a decisive role in the diffusion process. Initially, it is oriented normal to the surface, aligning in the electrostatic field of the surface during the adsorption process, but after resorption it lies parallel to the surface, being unable to return to its original orientation due to geometric constraints arising from structured water layers at the surface. Diffusion from this alternative adsorption state has a lower energy barrier of ∼0.9 eV, associated with breaking hydrogen bonds along the pathway, in reasonable agreement with the barrier inferred from previous experimental observation of lysozyme surface clustering. These results show the importance of studying protein diffusion alongside adsorption to gain full insight into the formation of protein clusters and films, essential steps in the future development of functionalized surfaces.
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Affiliation(s)
- Karina Kubiak-Ossowska
- Department of Chemical and Process Engineering, University of Strathclyde, Glasgow, United Kingdom
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11
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Westwood M, Kirby AR, Parker R, Morris VJ. Combined QCMD and AFM studies of lysozyme and poly-L-lysine-poly-galacturonic acid multilayers. Carbohydr Polym 2012; 89:1222-31. [PMID: 24750935 DOI: 10.1016/j.carbpol.2012.03.097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 01/31/2012] [Accepted: 03/31/2012] [Indexed: 11/15/2022]
Abstract
A quartz crystal microbalance with dissipation monitoring (QCMD) has been used to monitor the adsorption and structure of lysozyme monolayers and multilayers, and poly-L-lysine (PLL)-polygalacturonic acid (PGalA) multilayers at a solid-liquid interface using freshly-cleaved mica as a substrate. QCMD measurements were complemented with atomic force microscopy (AFM). AFM images revealed that lysozyme formed incomplete monolayers and provided a basis for calculation of the thickness of the protein film. Comparative studies of adsorption onto standard and mica-coated quartz crystals showed higher areal mass adsorption and a longer-time adsorption process for mica-coated quartz crystals. Simultaneous AFM images and QCMD data were obtained for lysozyme, linear PLL-PGalA and 7 nm PLL dendrimer-PGalA multilayers. The layer-by-layer deposited multilayer films exhibited viscoelastic properties and their growth followed a non-linear regime, associated with the PLL diffusion in and out of the film formation for linear PLL-PGalA films. For the PLL 7 nm dendrimer-PGalA films the AFM images revealed marked changes in surface roughness during layer by layer deposition: these changes influence the interpretation of the QCMD data and provide additional information on the growth and structure of the multilayers.
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Affiliation(s)
- Marta Westwood
- Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK
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12
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Kubiak-Ossowska K, Mulheran PA. Multiprotein interactions during surface adsorption: a molecular dynamics study of lysozyme aggregation at a charged solid surface. J Phys Chem B 2011; 115:8891-900. [PMID: 21671567 PMCID: PMC3662390 DOI: 10.1021/jp1121239] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 05/28/2011] [Indexed: 11/30/2022]
Abstract
Multiprotein adsorption of hen egg white lysozyme at a model charged ionic surface is studied using fully atomistic molecular dynamics simulations. Simulations with two, three, and five proteins, in various orientations with respect the surface, are performed over a 100 ns time scale. Mutated proteins with point mutations at the major (Arg128 and Arg125) and minor (Arg68) surface adsorption sites are also studied. The 100 ns time scale used is sufficient to observe protein translations, rotations, adsorption, and aggregation. Two competing processes of particular interest are observed, namely surface adsorption and protein-protein aggregation. At low protein concentration, the proteins first adsorb in isolation and can then reorientate on the surface to aggregate. At high concentration, the proteins aggregate in the solution and then adsorb in nonspecific ways. This work demonstrates the role of protein concentration in adsorption, indicates the residues involved in both types of interaction (protein-protein and protein-surface), and gives an insight into processes to be considered in the development of new functionalized material systems.
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Affiliation(s)
- Karina Kubiak-Ossowska
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziadzka 5/7, 87-100 Torun, Poland
| | - Paul A. Mulheran
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
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13
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Neogi P, Wang JC. Stability of two-dimensional growth of a packed body of proteins on a solid surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5347-5353. [PMID: 21473573 DOI: 10.1021/la104616b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Adsorption of proteins from the bulk is at times accompanied by a rearrangement which leads to the formation of closed packed bodies, that may or may not be crystalline. Mass transfer of protein molecules on a surface is modeled. Forced diffusion by van der Waals and electrostatic forces leads to segregation, which is eventually a different phase that is assumed to be thermodynamically favored. The net effective force in two-dimensions has been modeled approximately and shown to be much stronger and more long ranged than in the bulk: that is, under the same conditions, the protein molecules may not aggregate in the bulk they may aggregate on a surface. These forces have been used only indirectly but equivalently as an adsorption-desorption step at the interline. Eventually, a linear stability analysis of the growing body shows it to be unstable and would give rise to whiskers that are one molecule thick. This is what is observed experimentally. The conditions that give rise to the instability have been determined. The reverse case of rinsing of the protein molecules has also been studied experimentally and has been analyzed using the same mechanisms. Here it is seen that thicker inroads into the packed body cause the interline to take on a spongy appearance. It is conjectured that eventually islands will appear as seen in the experiments.
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Affiliation(s)
- P Neogi
- Chemical and Biological Engineering Department, Missouri University of Science and Technology, Rolla, Missouri 65409-1230, United States.
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14
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Understanding protein adsorption phenomena at solid surfaces. Adv Colloid Interface Sci 2011; 162:87-106. [PMID: 21295764 DOI: 10.1016/j.cis.2010.12.007] [Citation(s) in RCA: 986] [Impact Index Per Article: 75.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 12/21/2010] [Accepted: 12/28/2010] [Indexed: 11/21/2022]
Abstract
Protein adsorption at solid surfaces plays a key role in many natural processes and has therefore promoted a widespread interest in many research areas. Despite considerable progress in this field there are still widely differing and even contradictive opinions on how to explain the frequently observed phenomena such as structural rearrangements, cooperative adsorption, overshooting adsorption kinetics, or protein aggregation. In this review recent achievements and new perspectives on protein adsorption processes are comprehensively discussed. The main focus is put on commonly postulated mechanistic aspects and their translation into mathematical concepts and model descriptions. Relevant experimental and computational strategies to practically approach the field of protein adsorption mechanisms and their impact on current successes are outlined.
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15
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Nanomaterials in biological environment: a review of computer modelling studies. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2010; 40:103-15. [DOI: 10.1007/s00249-010-0651-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 11/18/2010] [Accepted: 11/23/2010] [Indexed: 01/13/2023]
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16
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Kubiak-Ossowska K, Mulheran PA. Mechanism of hen egg white lysozyme adsorption on a charged solid surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15954-65. [PMID: 20873744 DOI: 10.1021/la102960m] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The mechanism of hen egg white lysozyme (HEWL) adsorption on a negatively charged, hydrophilic surface has been studied using atomistic molecular dynamics (MD) simulation. Sixteen 90 ns trajectories provide adequate data to allow a detailed description of the adsorption process to be formulated. Two distinct adsorption sites have been identified. The main one is located on the N,C-terminal protein face and comprises Arg128 (the crucial one), supplemented by Arg125, Arg5, and Lys1; the minor one is used accidentally and contains only Arg68. Adsorption of this protein is driven by electrostatics, where the orientation of the protein dipole moment defines the direction of protein movement. The diffusion range on the surface depends on protein side-chain penetration through the surface water layers. This is facilitated by the long-range electric field of the charged surface, which can align polar side chains to be perpendicular to the surface. A simulation of adsorption onto a neutral ionic surface shows no such surface water layer penetration. Therefore, protein flexibility is seen to be an important factor, and to adsorb the HEWL has to adjust its structure. Nevertheless, at a flat surface only a slight loss of α-helical content is required. The adsorbed HEWL molecule is oriented between side-on and end-on ways, where the angle between the protein long axis (which mostly approximates the dipole moment) and the surface varies between 45° and 90°. Simulations with targeted mutations confirm the picture that emerges from these studies. The active site is located on the opposite face to the main adsorption site; hence, the activity of the immobilized HEWL should not be affected by the surface interactions. Our results provide a detailed insight into the adsorption mechanism and protein mobility at the surface. This knowledge will aid the proper interpretation of experimental results and the design of new experiments and functional systems.
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Affiliation(s)
- Karina Kubiak-Ossowska
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
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17
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Siegismund D, Keller TF, Jandt KD, Rettenmayr M. Fibrinogen Adsorption on Biomaterials - A Numerical Study. Macromol Biosci 2010; 10:1216-23. [DOI: 10.1002/mabi.201000120] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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18
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Kubiak-Ossowska K, Mulheran PA. What governs protein adsorption and immobilization at a charged solid surface? LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:7690-4. [PMID: 20433191 PMCID: PMC3689231 DOI: 10.1021/la101276v] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The adsorption of hen egg white lysozyme at a model charged surface is studied using fully atomistic molecular dynamics simulations. The simulations are performed over a 90 ns time scale which is sufficient to observe rotational and translational steps in the adsorption process. Electrostatics is found to play a key role in guiding the protein to the favorable binding orientation with the N,C-terminal face against the substrate. However, full immobilization appears to only occur through the strong interaction of Arg128 with the surface, facilitated by the protein's flexibility at the terminal face. Simulated mutation at this residue confirms its crucial role. This work demonstrates that electrostatics alone might not be sufficient to guide the development of material systems that exploit protein adsorption and immobilization.
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Affiliation(s)
- Karina Kubiak-Ossowska
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziadzka 5/7, 87-100 Torun, Poland
| | - Paul A. Mulheran
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
- To whom correspondence should be addressed. E-mail: . Telephone: +44 (0)141 548 2385
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19
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Rabe M, Verdes D, Seeger S. Understanding Cooperative Protein Adsorption Events at the Microscopic Scale: A Comparison between Experimental Data and Monte Carlo Simulations. J Phys Chem B 2010; 114:5862-9. [DOI: 10.1021/jp909601m] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael Rabe
- Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Dorinel Verdes
- Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Stefan Seeger
- Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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20
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Casero E, Vázquez L, Parra-Alfambra AM, Lorenzo E. AFM, SECM and QCM as useful analytical tools in the characterization of enzyme-based bioanalytical platforms. Analyst 2010; 135:1878-903. [DOI: 10.1039/c0an00120a] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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21
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Das SK, Das AR, Guha AK. Gold nanoparticles: microbial synthesis and application in water hygiene management. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8192-9. [PMID: 19425601 DOI: 10.1021/la900585p] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A green chemical method to synthesize nanogold-bioconjugate and its eco-friendly promising role to purify contaminated waters has been described. Gold nanoparticles of 10 nm average diameter are produced on the surface of Rhizopus oryzae , a fungal strain, by in situ reduction of chloroauric acid (HAuCl(4)). The nanogold-bioconjugate (NGBC) showed strong adsorption capacity toward different organophosphorous pesticides. The EDXA study confirms adsorption of pesticides on the conjugate material surface. Morphological changes of the NGBC material after adsorption of organophosphorous pesticides were detected by atomic force micrographs. NGBC shows high antimicrobial activity against several Gram-negative and Gram-positive pathogenic bacteria as well as the yeasts Saccharomyces cerevisiae and Candida albicans . The treatment of microbial cells with NGBC caused rupture of cell membrane as revealed in scanning electron and fluorescence micrographs. These unique characteristics of NGBC have been successfully utilized to obtain potable water free from pathogens and pesticides in a single operation.
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Affiliation(s)
- Sujoy K Das
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Kolkata, India.
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Madeira C, Estrela N, Ferreira JAB, Andrade SM, Costa SMB, Melo EP. Fluorescence lifetime imaging microscopy and fluorescence resonance energy transfer from cyan to yellow fluorescent protein validates a novel method to cluster proteins on solid surfaces. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:044035. [PMID: 19725746 DOI: 10.1117/1.3210770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel method to distribute proteins on solid surfaces is proposed. Proteins microencapsulated in the water pool of reverse micelles were used to coat a solid surface with well-individualized round spots of 1 to 3 microm in diameter. The number of spots per unit area can be increased through the concentration of reverse micelles, and networks of spots were obtained at high concentrations of large reverse micelles. Moreover, depending on the pool size of the water reverse micelles, proteins can be deposited far from each other or in close proximity within the range of 50 to 70 A. This proximity obtained with small reverse micelles was proved through fluorescence lifetime imaging microscopy and fluorescence resonance energy transfer (FLIM-FRET) measurements for the most relevant FRET pair in cell biology studies, the cyan and yellow fluorescent proteins. This novel procedure has several advantages and reveals the potential for study of protein-protein interactions on solid surfaces and for developing novel biomaterials and molecular devices based on biorecognition elements.
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Affiliation(s)
- Catarina Madeira
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Tecnico, Av Rovisco Pais, Lisbon, 1049-001, Portugal
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Kubiak K, Mulheran PA. Molecular Dynamics Simulations of Hen Egg White Lysozyme Adsorption at a Charged Solid Surface. J Phys Chem B 2009; 113:12189-200. [DOI: 10.1021/jp901521x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Karina Kubiak
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom, and Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziadzka 5/7, 87-100 Torun, Poland
| | - Paul A. Mulheran
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom, and Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziadzka 5/7, 87-100 Torun, Poland
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Mulheran P, Kubiak K. Protein adsorption mechanisms on solid surfaces: lysozyme-on-mica. MOLECULAR SIMULATION 2009. [DOI: 10.1080/08927020802610288] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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