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Mao S, Sarkar A, Wang Y, Song C, LeVine D, Wang X, Que L. Microfluidic chip grafted with integrin tension sensors for evaluating the effects of flowing shear stress and ROCK inhibitor on platelets. LAB ON A CHIP 2021; 21:3128-3136. [PMID: 34180491 PMCID: PMC8353964 DOI: 10.1039/d1lc00259g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Integrins are key players in platelet adhesion and aggregation. Integrin molecular tensions, the forces transmitted by integrin molecules, are regulated by both mechanical and biochemical cues, and the outside-in and inside-out signaling has been extensively studied. While the mechanical properties of platelets at static status have been studied by atomic force microscopy, traction force microscopy and tension sensors, the biomechanical properties of flowing platelets remain elusive. Herein, we report microfluidic chips grafted with integrin tension sensors for microfluidic-force mapping in platelets. Specifically, the process of integrin αIIbβ3 mediating tension transmission and platelet adhesion under low flow rates has been obtained, and the process of platelet clustering at post-stenotic regions has been demonstrated. We found that flowing shear force can postpone the integrin-mediated tension transmission and platelet adhesion. We further evaluated the effect of Y-27632, a ROCK inhibitor that has been proven to reduce integrin-mediated platelet adhesion, at a series of concentrations and demonstrated that microfluidic chips with integrin tension sensors are sensitive to the concentration-dependent effects of Y-27632. Given their low cost and scalable throughput, these chips are ideal technical platforms for biological studies of platelets at flowing status and for platelet inhibitor or potential antiplatelet drug screening.
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Affiliation(s)
- Subin Mao
- Electrical and Computer Engineering Department, Iowa State University, Ames, USA50011.
| | - Anwesha Sarkar
- Electrical and Computer Engineering Department, Iowa State University, Ames, USA50011. and Department of Physics and Astronomy, Iowa State University, Ames, USA50011.
| | - Yongliang Wang
- Department of Physics and Astronomy, Iowa State University, Ames, USA50011.
| | - Chao Song
- Electrical and Computer Engineering Department, Iowa State University, Ames, USA50011.
| | - Dana LeVine
- Veterinary Clinical Sciences, Iowa State University, Ames, USA50011
| | - Xuefeng Wang
- Department of Physics and Astronomy, Iowa State University, Ames, USA50011.
| | - Long Que
- Electrical and Computer Engineering Department, Iowa State University, Ames, USA50011.
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2
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Nitrosative stress affects the interaction of integrin alphaIIbbeta3 with its ligands. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183198. [DOI: 10.1016/j.bbamem.2020.183198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 11/17/2022]
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3
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Abstract
Interactions between ligands and receptors and subsequent "locking" must involve some resistance to unbinding, manifesting itself as an interaction force. At body temperature, spontaneous unbinding will occur, however, external forces are required to accelerate this process. Bearing in mind the potential forces that the receptor-ligand complex is likely to be subjected to in a biological environment, it might be hypothesised that there is some mechanical matching between the receptor and ligand. To test this hypothesis, various receptor and ligand pairs were unfolded in their entirety in order to determine their total unfolding force. In this way, the total force to unfold the protein could be determined, allowing a comparison between ligand and receptor pairs. The interest of this work is to examine the interaction between five proteins and a mica surface by AFM without any modification to preserve the natural elastic properties of the protein molecules during the force measurements. The results showed a mechanical matching between GP120 (ligand) and CD4 (receptor) when analysing the total force required to unfold the same number of domains or events shown by the force distance curves of these proteins.
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Affiliation(s)
- Ana Peñaherrera
- Department of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
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4
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Wu Z, Xu Z, Kim O, Alber M. Three-dimensional multi-scale model of deformable platelets adhesion to vessel wall in blood flow. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:rsta.2013.0380. [PMID: 24982253 PMCID: PMC4084525 DOI: 10.1098/rsta.2013.0380] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
When a blood vessel ruptures or gets inflamed, the human body responds by rapidly forming a clot to restrict the loss of blood. Platelets aggregation at the injury site of the blood vessel occurring via platelet-platelet adhesion, tethering and rolling on the injured endothelium is a critical initial step in blood clot formation. A novel three-dimensional multi-scale model is introduced and used in this paper to simulate receptor-mediated adhesion of deformable platelets at the site of vascular injury under different shear rates of blood flow. The novelty of the model is based on a new approach of coupling submodels at three biological scales crucial for the early clot formation: novel hybrid cell membrane submodel to represent physiological elastic properties of a platelet, stochastic receptor-ligand binding submodel to describe cell adhesion kinetics and lattice Boltzmann submodel for simulating blood flow. The model implementation on the GPU cluster significantly improved simulation performance. Predictive model simulations revealed that platelet deformation, interactions between platelets in the vicinity of the vessel wall as well as the number of functional GPIbα platelet receptors played significant roles in platelet adhesion to the injury site. Variation of the number of functional GPIbα platelet receptors as well as changes of platelet stiffness can represent effects of specific drugs reducing or enhancing platelet activity. Therefore, predictive simulations can improve the search for new drug targets and help to make treatment of thrombosis patient-specific.
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Affiliation(s)
- Ziheng Wu
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Zhiliang Xu
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Oleg Kim
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Mark Alber
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN 46556, USA Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Handa H, Major TC, Brisbois EJ, Amoako KA, Meyerhoff ME, Bartlett RH. Hemocompatibility Comparison of Biomedical Grade Polymers Using Rabbit Thrombogenicity Model for Preparing Nonthrombogenic Nitric Oxide Releasing Surfaces. J Mater Chem B 2014; 2:1059-1067. [PMID: 24634777 DOI: 10.1039/c3tb21771j] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion/activation. Nitric oxide releasing (NOrel) materials can be prepared by doping an NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2), within a polymer coating. The inherent hemocompatibility properties of the base polymer can also influence the efficiency of such NO release coatings. In this study, four biomedical grade polymers were evaluated in a 4 h rabbit model of thrombogenicity for their effects on extracorporeal circuit thrombus formation and circulating platelet count. At the end of 4 h, Elast-Eon E2As was found to preserve 58% of baseline platelets versus 48, 40, and 47% for PVC/DOS, Tecophilic SP-60D-60, and Tecoflex SG80A, respectively. Elast-Eon also had significantly lower clot area of 5.2 cm2 compared to 6.7, 6.1, and 6.9 cm2 for PVC/DOS, SP-60D-60, and SG80A, respectively. Based on the results obtained for the base polymer comparison study, DBHD/N2O2-doped E2As was evaluated in short-term (4 h) rabbit studies to observe the NO effects on prevention of clotting and preservation of platelet function. Platelet preservation for this optimal NO release formulation was 97% of baseline after 4 h, and clot area was 0.9 cm2 compared to 5.2 cm2 for controls, demonstrating that combining E2As with NO release provides a truly advanced hemocompatible polymer coating for extracorporeal circuits and potentially other blood contacting applications.
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Affiliation(s)
- Hitesh Handa
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI USA
| | - Terry C Major
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI USA
| | | | - Kagya A Amoako
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI USA
| | - Mark E Meyerhoff
- Department of Chemistry, University of Michigan, Ann Arbor, MI USA
| | - Robert H Bartlett
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI USA
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6
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Whited AM, Park PSH. Atomic force microscopy: a multifaceted tool to study membrane proteins and their interactions with ligands. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:56-68. [PMID: 23603221 DOI: 10.1016/j.bbamem.2013.04.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/22/2013] [Accepted: 04/09/2013] [Indexed: 01/31/2023]
Abstract
Membrane proteins are embedded in lipid bilayers and facilitate the communication between the external environment and the interior of the cell. This communication is often mediated by the binding of ligands to the membrane protein. Understanding the nature of the interaction between a ligand and a membrane protein is required to both understand the mechanism of action of these proteins and for the development of novel pharmacological drugs. The highly hydrophobic nature of membrane proteins and the requirement of a lipid bilayer for native function have hampered the structural and molecular characterizations of these proteins under physiologically relevant conditions. Atomic force microscopy offers a solution to studying membrane proteins and their interactions with ligands under physiologically relevant conditions and can provide novel insights about the nature of these critical molecular interactions that facilitate cellular communication. In this review, we provide an overview of the atomic force microscopy technique and discuss its application in the study of a variety of questions related to the interaction between a membrane protein and a ligand. This article is part of a Special Issue entitled: Structural and biophysical characterization of membrane protein-ligand binding.
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Affiliation(s)
- Allison M Whited
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
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7
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Activation induced morphological changes and integrin αIIbβ3 activity of living platelets. Methods 2013; 60:179-85. [PMID: 23571313 PMCID: PMC3678024 DOI: 10.1016/j.ymeth.2013.03.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/04/2013] [Accepted: 03/30/2013] [Indexed: 11/22/2022] Open
Abstract
Platelets are essential in hemostasis. Upon activation they undergo a shape-change accompanied with receptor presentation. Atomic force microscopy (AFM) imaging and single molecule force spectroscopy (SMFS) were used as powerful tools for exploring morphological changes as well as receptor activities of platelets. Imaging time series was accomplished with and without fixation steps at the single platelet level. Hereby the response of mechanical stimulation of the platelet by the AFM cantilever tip was directly observed. We demonstrate that living and fixed platelets develop filopodia after a short activation time followed by their disappearance including cellular bleb formation. Thereafter a second filopodia formation (filopodia extrusion) was observed; those filopodia subsequently disappeared again, and finally platelets detached from the support due to cell death. We determined the influence of mechanical stress on the chronology of morphological changes of platelets and demonstrated shear force induced filopodia formation. Through recordings over several hours, topographical AFM images over the full platelet lifetime - from early activation up to apoptosis - are presented. SMFS measurements on living platelets allowed determining the activation state of the most prominent membrane receptor integrin αIIbβ3 at all different phases of activation. αIIbβ3 was fully activated, independent of the morphological state.
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8
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Nanoscale characterization of cell receptors and binding sites on cell-derived extracellular matrices. Ultramicroscopy 2012; 118:44-52. [DOI: 10.1016/j.ultramic.2012.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/20/2012] [Accepted: 04/20/2012] [Indexed: 01/16/2023]
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9
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Litvinov RI, Barsegov V, Schissler AJ, Fisher AR, Bennett JS, Weisel JW, Shuman H. Dissociation of bimolecular αIIbβ3-fibrinogen complex under a constant tensile force. Biophys J 2011; 100:165-73. [PMID: 21190668 DOI: 10.1016/j.bpj.2010.11.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 11/08/2010] [Accepted: 11/16/2010] [Indexed: 02/07/2023] Open
Abstract
The regulated ability of integrin αIIbβ3 to bind fibrinogen plays a crucial role in platelet aggregation, adhesion, and hemostasis. Employing an optical-trap-based electronic force clamp, we studied the thermodynamics and kinetics of αIIbβ3-fibrinogen bond formation and dissociation under constant unbinding forces, mimicking the forces of physiologic blood shear on a thrombus. The distribution of bond lifetimes was bimodal, indicating that the αIIbβ3-fibrinogen complex exists in two bound states with different mechanical stability. The αIIbβ3 antagonist, abciximab, inhibited binding without affecting the unbinding kinetics, whereas Mn²(+) biased the αIIbβ3-fibrinogen complex to the strong bound state with reduced off-rate. The average bond lifetimes decreased exponentially with increasing pulling force from ∼5 pN to 50 pN, suggesting that in this force range the αIIbβ3-fibrinogen interactions are classical slip bonds. We found no evidence for catch bonds, which is consistent with the known lack of shear-enhanced platelet adhesion on fibrinogen-coated surfaces. Taken together, these data provide important quantitative and qualitative characteristics of αIIbβ3-fibrinogen binding and unbinding that underlie the dynamics of platelet adhesion and aggregation in blood flow.
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Affiliation(s)
- Rustem I Litvinov
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
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10
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Xu LC, Siedlecki CA. Microphase separation structure influences protein interactions with poly(urethane urea) surfaces. J Biomed Mater Res A 2010; 92:126-36. [DOI: 10.1002/jbm.a.32340] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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11
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Averett LE, Schoenfisch MH. Atomic force microscope studies of fibrinogen adsorption. Analyst 2010; 135:1201-9. [DOI: 10.1039/b924814e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Garner AE, Smith DA, Hooper NM. Sphingomyelin chain length influences the distribution of GPI-anchored proteins in rafts in supported lipid bilayers. Mol Membr Biol 2009; 24:233-42. [PMID: 17520480 DOI: 10.1080/09687860601127770] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glycosyl-phosphatidylinositol (GPI)-anchored proteins are enriched in cholesterol- and sphingolipid-rich lipid rafts within the membrane. Rafts are known to have roles in cellular organization and function, but little is understood about the factors controlling the distribution of proteins in rafts. We have used atomic force microscopy to directly visualize proteins in supported lipid bilayers composed of equimolar sphingomyelin, dioleoyl-sn-glycero-3-phosphocholine and cholesterol. The transmembrane anchored angiotensin converting enzyme (TM-ACE) was excluded from the liquid ordered raft domains. Replacement of the transmembrane and cytoplasmic domains of TM-ACE with a GPI anchor (GPI-ACE) promoted the association of the protein with rafts in the bilayers formed with brain sphingomyelin (mainly C18:0). Association with the rafts did not occur if the shorter chain egg sphingomyelin (mainly C16:0) was used. The distribution of GPI-anchored proteins in supported lipid bilayers was investigated further using membrane dipeptidase (MDP) whose GPI anchor contains distearoyl phosphatidylinositol. MDP was also excluded from rafts when egg sphingomyelin was used but associated with raft domains formed using brain sphingomyelin. The effect of sphingomyelin chain length on the distribution of GPI-anchored proteins in rafts was verified using synthetic palmitoyl or stearoyl sphingomyelin. Both GPI-ACE and MDP only associated with the longer chain stearoyl sphingomyelin rafts. These data obtained using supported lipid bilayers provide the first direct evidence that the nature of the membrane-anchoring domain influences the association of a protein with lipid rafts and that acyl chain length hydrophobic mismatch influences the distribution of GPI-anchored proteins in rafts.
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Affiliation(s)
- Ashley E Garner
- Proteolysis Research Group, Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, and Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, UK
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13
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Xu LC, Siedlecki CA. Atomic force microscopy studies of the initial interactions between fibrinogen and surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3675-81. [PMID: 19275182 PMCID: PMC2749234 DOI: 10.1021/la803258h] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Atomic force microscopy (AFM) was used to analyze the interactions between fibrinogen and model surfaces having different levels of water wettability. In contrast to most AFM studies, proteins were coupled to the substrate while model surface colloids were attached to the end of the AFM probe, thereby ensuring that proteins undergo only a single compression/decompression cycle. Similar values of adhesion force were observed between fibrinogen and all of the highly wettable surfaces; in the same manner, fibrinogen showed similar adhesion forces against all poorly wettable surfaces, with a step-like transition observed between the two groups. Relationships between the adhesion forces and loading rates were used to analyze the energy profiles involved in protein/surface interactions. Multiple energy barriers were found in the interaction of proteins with poorly wettable surfaces; whereas a single energy barrier was found for protein interactions with highly wettable surfaces. Contact time-dependent adhesion data were fit to an exponential model and showed that the rate constants of the protein unfolding process on highly wettable surface were smaller at low loading rates, but increased rapidly to yield values similar to those on poorly wettable surfaces at high loading rates. The activation energies of protein unfolding derived from the data offer insight into the role of surface wettability in affecting adhesion, conformational changes, and ultimately, the activity of proteins at biomaterial surfaces.
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Affiliation(s)
- Li-Chong Xu
- Department of Surgery, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
| | - Christopher A. Siedlecki
- Department of Surgery, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
- Department of Bioengineering, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
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14
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Plomp M, Malkin AJ. Mapping of proteomic composition on the surfaces of bacillus spores by atomic force microscopy-based immunolabeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:403-409. [PMID: 19063625 DOI: 10.1021/la803129r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Atomic force microscopy (AFM) provides a unique capability to image high-resolution architecture and structural dynamics of pathogens (e.g., viruses, bacteria, and bacterial spores) at near-molecular resolution in native conditions. Further development of atomic force microscopy to enable the correlation of pathogen protein surface structures with specific gene products is essential to understand the mechanisms of the pathogen life cycle. We applied an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures through the visualization of the binding of antibodies, conjugated with nanogold particles, to specific epitopes on Bacillus spore surfaces. This information is generated while simultaneously acquiring the surface morphology of the pathogen. The immunospecificity of this labeling method was established through the utilization of specific polyclonal and monoclonal antibodies that target spore coat and exosporium epitopes of Bacillus atrophaeus and Bacillus anthracis spores.
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Affiliation(s)
- Marco Plomp
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, L-233, Livermore, California 94551, USA
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15
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Goksu EI, Vanegas JM, Blanchette CD, Lin WC, Longo ML. AFM for structure and dynamics of biomembranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:254-66. [DOI: 10.1016/j.bbamem.2008.08.021] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 08/26/2008] [Accepted: 08/31/2008] [Indexed: 12/17/2022]
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16
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Soman P, Rice Z, Siedlecki CA. Immunological identification of fibrinogen in dual-component protein films by AFM imaging. Micron 2008; 39:832-42. [PMID: 18294855 PMCID: PMC2637371 DOI: 10.1016/j.micron.2007.12.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 12/18/2007] [Accepted: 12/21/2007] [Indexed: 11/16/2022]
Abstract
The success of long-term blood-contacting implanted devices is largely dependent upon the interaction of the blood components with the device biomaterial surface. The ability to study these interactions has been hindered by a lack of methods to measure single-molecule interactions in complex multi-protein environments similar to the environment found in vivo. In this paper, we demonstrate the use of atomic force microscopy (AFM) in conjunction with gold nanolabels to detect the protein fibrinogen under aqueous conditions without the topographical clues usually necessary for high resolution visualization. BSA was patterned onto both muscovite mica and plasma-treated polydimethylsiloxane (PDMS) substrates and these test substrates were subsequently backfilled with fibrinogen to yield a featureless protein layer. The fibrinogen in this dual-protein layer was detected using high resolution AFM imaging following infusion of anti-fibrinogen conjugated with nanogold particles. This AFM immuno-detection technique will potentially be applicable to complex multi-component protein films adsorbed on clinically relevant polymers used in medical devices.
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Affiliation(s)
- Pranav Soman
- Department of Bioengineering, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
| | - Zachary Rice
- Department of Surgery, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
| | - Christopher A. Siedlecki
- Department of Bioengineering, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
- Department of Surgery, Biomedical Engineering Institute, The Pennsylvania State University, College of Medicine, Hershey, PA, 17033
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17
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Soman P, Rice Z, Siedlecki CA. Measuring the time-dependent functional activity of adsorbed fibrinogen by atomic force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8801-8806. [PMID: 18616311 DOI: 10.1021/la801227e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In this work, we measured time-dependent functional changes in adsorbed fibrinogen by measuring antigen-antibody debonding forces with atomic force microscopy (AFM). AFM probes were functionalized with monoclonal antibodies recognizing fibrinogen gamma 392-411, which includes the platelet binding dodecapeptide region. These probes were used to collect force measurements between the antibody and fibrinogen on mica substrates and the probability of antigen recognition was calculated. Statistical analysis showed that the probability of antibody-antigen recognition peaked at approximately 45 min postadsorption and decreased with increasing residence time. Macroscale platelet adhesion measurements on these mica substrates were determined to be greatest at fibrinogen residence times of approximately 45 min, which correlated well with the functional activity of adsorbed fibrinogen as measured by the modified AFM probes. These results demonstrate the utility of this approach for measuring protein function at or near the molecular scale and offers new opportunities for improved insights into the molecular basis for the biological response to biomaterials.
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Affiliation(s)
- Pranav Soman
- Department of Bioengineering and Surgery, The Pennsylvania State University College of Medicine, Hershey Pennsylvania 17033, USA
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18
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Hantgan RR, Stahle MC, Horita DA. Entropy Drives Integrin αIIbβ3:Echistatin Binding—Evidence from Surface Plasmon Resonance Spectroscopy. Biochemistry 2008; 47:2884-92. [DOI: 10.1021/bi701877a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Roy R. Hantgan
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016
| | - Mary C. Stahle
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016
| | - David A. Horita
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016
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19
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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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20
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Arnaout MA, Goodman SL, Xiong JP. Structure and mechanics of integrin-based cell adhesion. Curr Opin Cell Biol 2007; 19:495-507. [PMID: 17928215 DOI: 10.1016/j.ceb.2007.08.002] [Citation(s) in RCA: 251] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Accepted: 08/14/2007] [Indexed: 01/09/2023]
Abstract
Integrins are alpha/beta heterodimeric adhesion glycoprotein receptors that regulate a wide variety of dynamic cellular processes such as cell migration, phagocytosis, and growth and development. X-ray crystallography of the integrin ectodomain revealed its modular architecture and defined its metal-dependent interaction with extracellular ligands. This interaction is regulated from inside the cell (inside-out activation), through the short cytoplasmic alpha and beta integrin tails, which also mediate biochemical and mechanical signals transmitted to the cytoskeleton by the ligand-occupied integrins, effecting major changes in cell shape, behavior, and fate. Recent advances in the structural elucidation of integrins and integrin-binding cytoskeleton proteins are the subjects of this review.
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Affiliation(s)
- M Amin Arnaout
- Nephrology Division, Leukocyte Biology & Inflammation Program, Structural Biology Program, Massachusetts General Hospital, and Harvard Medical School, 149 13th Street, Charlestown, MA 02129, United States.
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Arntz Y, Jourdainne L, Greiner-Wacker G, Rinckenbach S, Ogier J, Voegel JC, Lavalle P, Vautier D. Immunogold detection of types I and II chondrocyte collagen fibrils: An in situ atomic force microscopic investigation. Microsc Res Tech 2006; 69:283-90. [PMID: 16586488 DOI: 10.1002/jemt.20313] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Chondrocyte tissue engineering is a major challenge in the field of cartilage repair. The phenotype of chondrocytes consists of cartilage specific proteoglycan and type II collagen. During serial passages, chondrocytes dedifferentiate into cells, presenting a fibroblast-like phenotype consisting predominately of type I collagen synthesis. Observation of native collagen fibers could be visualized by atomic force microscope. Here, we developed an original and useful atomic force microscopy-based immunogold technique allowing biochemical distinction between types I and II collagen fibers. Imaging of 40-nm gold particles staining collagen fibers was performed in tapping mode. Rat 1 fibroblasts and human chondrosarcoma cells were used as positive models for types I and II collagen, respectively. As demonstrated by our data, primary rat chondrocytes adhering for 48 h on a glass substrate synthesize type II collagen native fibers. This technique allows analyses of local areas of the extracellular matrix of fixed cells, providing complementary data about cartilage phenotype. This simple approach could be of major interest for the biologist community in routine laboratory investigations, to localize in situ, macromolecules of the extracellular matrix.
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Shaw JE, Oreopoulos J, Wong D, Hsu JCY, Yip CM. Coupling evanescent-wave fluorescence imaging and spectroscopy with scanning probe microscopy: challenges and insights from TIRF–AFM. SURF INTERFACE ANAL 2006. [DOI: 10.1002/sia.2444] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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