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Dam T, Chouliara M, Junghans V, Jönsson P. Supported Lipid Bilayers and the Study of Two-Dimensional Binding Kinetics. Front Mol Biosci 2022; 9:833123. [PMID: 35252352 PMCID: PMC8896763 DOI: 10.3389/fmolb.2022.833123] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/27/2022] [Indexed: 11/13/2022] Open
Abstract
Binding between protein molecules on contacting cells is essential in initiating and regulating several key biological processes. In contrast to interactions between molecules in solution, these events are restricted to the two-dimensional (2D) plane of the meeting cell surfaces. However, converting between the more commonly available binding kinetics measured in solution and the so-called 2D binding kinetics has proven a complicated task since for the latter several factors other than the protein-protein interaction per se have an impact. A few important examples of these are: protein density, membrane fluctuations, force on the bond and the use of auxiliary binding molecules. The development of model membranes, and in particular supported lipid bilayers (SLBs), has made it possible to simplify the studied contact to analyze these effects and to measure 2D binding kinetics of individual protein-protein interactions. We will in this review give an overview of, and discuss, how different SLB systems have been used for this and compare different methods to measure binding kinetics in cell-SLB contacts. Typically, the SLB is functionalized with fluorescently labelled ligands whose interaction with the corresponding receptor on a binding cell can be detected. This interaction can either be studied 1) by an accumulation of ligands in the cell-SLB contact, whose magnitude depends on the density of the proteins and binding affinity of the interaction, or 2) by tracking single ligands in the SLB, which upon interaction with a receptor result in a change of motion of the diffusing ligand. The advantages and disadvantages of other methods measuring 2D binding kinetics will also be discussed and compared to the fluorescence-based methods. Although binding kinetic measurements in cell-SLB contacts have provided novel information on how ligands interact with receptors in vivo the number of these measurements is still limited. This is influenced by the complexity of the system as well as the required experimental time. Moreover, the outcome can vary significantly between studies, highlighting the necessity for continued development of methods to study 2D binding kinetics with higher precision and ease.
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Affiliation(s)
- Tommy Dam
- Department of Chemistry, Lund University, Lund, Sweden
| | | | - Victoria Junghans
- Nuffield Department of Medicine, CAMS Oxford Institute, University of Oxford, Oxford, United Kingdom
| | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden
- *Correspondence: Peter Jönsson,
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2
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Lee D, Jung WH, Lee S, Yu ES, Lee T, Kim JH, Song HS, Lee KH, Lee S, Han SK, Choi MC, Ahn DJ, Ryu YS, Kim C. Ionic contrast across a lipid membrane for Debye length extension: towards an ultimate bioelectronic transducer. Nat Commun 2021; 12:3741. [PMID: 34145296 PMCID: PMC8213817 DOI: 10.1038/s41467-021-24122-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 06/03/2021] [Indexed: 11/09/2022] Open
Abstract
Despite technological advances in biomolecule detections, evaluation of molecular interactions via potentiometric devices under ion-enriched solutions has remained a long-standing problem. To avoid severe performance degradation of bioelectronics by ionic screening effects, we cover probe surfaces of field effect transistors with a single film of the supported lipid bilayer, and realize respectable potentiometric signals from receptor-ligand bindings irrespective of ionic strength of bulky solutions by placing an ion-free water layer underneath the supported lipid bilayer. High-energy X-ray reflectometry together with the circuit analysis and molecular dynamics simulation discovered biochemical findings that effective electrical signals dominantly originated from the sub-nanoscale conformational change of lipids in the course of receptor-ligand bindings. Beyond thorough analysis on the underlying mechanism at the molecular level, the proposed supported lipid bilayer-field effect transistor platform ensures the world-record level of sensitivity in molecular detection with excellent reproducibility regardless of molecular charges and environmental ionic conditions.
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Affiliation(s)
- Donggeun Lee
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea.,Department of Electrical & Electronic Engineering, Yonsei University, Seoul, Republic of Korea
| | - Woo Hyuk Jung
- Department of Chemical and Biological Engineering, Korea University, Seoul, Republic of Korea
| | - Suho Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Eui-Sang Yu
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Taikjin Lee
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Jae Hun Kim
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Hyun Seok Song
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Kwan Hyi Lee
- Center for Biomaterials, Korea Institute of Science and Technology, Seoul, Republic of Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea
| | - Seok Lee
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Sang-Kook Han
- Department of Electrical & Electronic Engineering, Yonsei University, Seoul, Republic of Korea
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Dong June Ahn
- Department of Chemical and Biological Engineering, Korea University, Seoul, Republic of Korea. .,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea.
| | - Yong-Sang Ryu
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea. .,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea.
| | - Chulki Kim
- Sensor System Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea.
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3
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Roces CB, Khadke S, Christensen D, Perrie Y. Scale-Independent Microfluidic Production of Cationic Liposomal Adjuvants and Development of Enhanced Lymphatic Targeting Strategies. Mol Pharm 2019; 16:4372-4386. [DOI: 10.1021/acs.molpharmaceut.9b00730] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Carla B. Roces
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
| | - Swapnil Khadke
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
| | - Dennis Christensen
- Center for Vaccine Research, Statens Serum Institut, DK-2300 Copenhagen, Denmark
| | - Yvonne Perrie
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
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4
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Quantum dot effects upon the interaction between porphyrins and phospholipids in cell membrane models. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 45:219-27. [DOI: 10.1007/s00249-015-1088-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/09/2015] [Indexed: 01/07/2023]
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5
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Whateley TL. Literature Alerts. Drug Deliv 2008. [DOI: 10.3109/10717549609031381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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6
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Literature Alerts. J Microencapsul 2008. [DOI: 10.3109/02652049609026022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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7
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Literature Alerts. J Microencapsul 2008. [DOI: 10.3109/02652049609052911] [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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8
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Whateley TL. Literature Alerts. Drug Deliv 2008. [DOI: 10.3109/10717549609031183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Yang J, Sun Y, Wu W, Chen Y, Sui SF. Binding of HIV gp41 with its Receptors Immobilized at Liquid/Solid Interface Studied by Surface Plasmon Resonance. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259908023478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jun Yang
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
| | - Yutong Sun
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
| | - Weichen Wu
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
| | - Yinghua Chen
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
| | - Sen-Fang Sui
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
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10
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Zhou Y, Caide X, Sui SF. Assembly of Supported Membranes Studied by Surface Plasmon Microscopy. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259908023377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Yue Zhou
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
| | - Xiao Caide
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
| | - Sen-Fang Sui
- a Department of Biological Sciences and Biotechnology , Tsinghua University , Beijing , 100084 , People's Republic of China
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11
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Li RF, Zhang F, Lu YJ, Sui SF. Specific interaction between Smad1 and CHIP: a surface plasmon resonance study. Colloids Surf B Biointerfaces 2005; 40:133-6. [PMID: 15708501 DOI: 10.1016/j.colsurfb.2004.10.013] [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: 01/08/2023]
Abstract
The TGF-beta superfamily signaling pathway regulates many important biological processes, including cell growth, differentiation and embryonic pattern formation. Smad1, a member of this signaling pathway that functions downstream of serine/threonine kinase receptors, has ability to interact with carboxyl terminus of Hsc70-interacting protein (CHIP), which is an E3 ubiquitin ligase in other cases. It has been reported that Smurf1, a member of the Hect family E3 ubiquitin ligases, can target Smad1 to 26S proteasome for degradation. In this paper, we studied the interaction of Smad1 and CHIP by combination of surface plasmon resonance and supported monolayer approach. The specific binding of Smad1 to CHIP indicates that the degradation of Smad1 may also be mediated by CHIP, and CHIP may play an essential role in the TGF-beta signaling pathway.
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Affiliation(s)
- Ren-Feng Li
- Department of Biological Sciences and Biotechnology, State-Key Laboratory of Biomembrane, Tsinghua University, Beijing 100084, PR China
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12
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Prachayasittikul V, Isarankura Na Ayudhya C, Hilterhaus L, Hinz A, Tantimongcolwat T, Galla HJ. Interaction analysis of chimeric metal-binding green fluorescent protein and artificial solid-supported lipid membrane by quartz crystal microbalance and atomic force microscopy. Biochem Biophys Res Commun 2005; 327:174-82. [PMID: 15629446 DOI: 10.1016/j.bbrc.2004.11.150] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2004] [Indexed: 10/26/2022]
Abstract
Non-specific adsorption and specific interaction between a chimeric green fluorescent protein (GFP) carrying metal-binding region and the immobilized zinc ions on artificial solid-supported lipid membranes was investigated using the quartz crystal microbalance technique and the atomic force microscopy (AFM). Supported lipid bilayer, composed of octanethiol and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycero-3-[N-(5-amino-1-carboxypentyl iminodiacetic acid)succinyl] (NTA-DOGS)-Zn2+, was formed on the gold electrode of quartz resonator (5 MHz). Binding of the chimeric GFP to zinc ions resulted in a rapid decrease of resonance frequency. Reversibility of the process was demonstrated via the removal of metal ions by EDTA. Nanoscale structural orientation of the chimeric GFP on the membrane was imaged by AFM. Association constant of the specific binding to metal ions was 2- to 3-fold higher than that of the non-specific adsorption, which was caused by the fluidization effect of the metal-chelating lipid molecules as well as the steric hindrance effect. This infers a possibility for a further development of biofunctionalized membrane. However, maximization is needed in order to attain closer advancement to a membrane-based sensor device.
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Affiliation(s)
- Virapong Prachayasittikul
- Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand.
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13
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Chen DL, Lu YJ, Sui SF, Xu B, Hu KS. Oriented Assembly of Purple Membrane on Solid Support, Mediated by Molecular Recognition. J Phys Chem B 2003. [DOI: 10.1021/jp022400+] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Wang F, Xia XF, Sui SF. Human apolipoprotein H may have various orientations when attached to lipid layer. Biophys J 2002; 83:985-93. [PMID: 12124280 PMCID: PMC1302202 DOI: 10.1016/s0006-3495(02)75224-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Apolipoprotein H (ApoH), also known as beta(2)-glycoprotein I, is a plasma glycoprotein with its in vivo physiological and pathogenic roles being closely related to its interaction with negatively charged membranes. Although the three-dimensional crystal structure of ApoH has been recently solved, direct evidence about the spatial state of ApoH on the membrane is still lacking. In this work, the interactions of ApoH with the lipid layer are studied by a combination of lipid monolayer approach and surface concentration determination. The spatial state of the orientation of ApoH on the lipid layer is investigated by analyzing the process of membrane-attached ApoH molecules being extruded out from the phospholipid monolayer by compression. The results show that on neutral lipid layer ApoH has an upright orientation, which is not sensitive to the phase state of the lipid layer. However, on acidic lipid layer, ApoH may have two forms of orientation. One is an upright orientation in the liquid phase region, and the other is flat orientation on the condensed domain region. The variation of the spatial state of ApoH on the lipid layer may relate to a variety of its physiological functions.
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Affiliation(s)
- Fu Wang
- Department of Biological Sciences and Biotechnology, State-Key Laboratory of Biomembrane, Tsinghua University, Beijing 100084, People's Republic of China
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15
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Hekman M, Hamm H, Villar AV, Bader B, Kuhlmann J, Nickel J, Rapp UR. Associations of B- and C-Raf with cholesterol, phosphatidylserine, and lipid second messengers: preferential binding of Raf to artificial lipid rafts. J Biol Chem 2002; 277:24090-102. [PMID: 11953426 DOI: 10.1074/jbc.m200576200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The serine/threonine kinase C-Raf is a key mediator in cellular signaling. Translocation of Raf to membranes has been proposed to be facilitated by Ras proteins in their GTP-bound state. In this study we provide evidence that both purified B- and C-Raf kinases possess lipophilic properties and associate with phospholipid membranes. In the presence of phosphatidylserine and lipid second messengers such as phosphatidic acid and ceramides these associations were very specific with affinity constants (K(D)) in the range of 0.5-50 nm. Raf association with liposomes was accompanied by displacement of 14-3-3 proteins and inhibition of Raf kinase activities. Interactions of Raf with cholesterol are of particular interest, since cholesterol has been shown to be involved, together with sphingomyelin and glycerophospholipids in the formation of specialized lipid microdomains called rafts. We demonstrate here that purified Raf proteins have moderate binding affinity for cholesterol. However, under conditions of lipid raft formation, Raf association with cholesterol (or rafts) increased dramatically. Since ceramides also support formation of rafts and interact with Raf we propose that Raf may be present at the plasma membrane in two distinct microdomains: in raft regions via association with cholesterol and ceramides and in non-raft regions due to interaction with phosphatidylserine and phosphatidic acid. At either location Raf kinase activity was inhibited by lipid binding in the absence or presence of Ras. Ras-Raf interactions with full-length C-Raf were studied both in solution and in phospholipid environment. Ras association with Raf was GTP dependent as previously demonstrated for C-Raf-RBD fragments. In the presence of liposomes the recruitment of C-Raf by reconstituted Ras-farnesyl was only marginal, since almost 70% of added C-Raf was bound by the lipids alone. Thus Ras-Raf binding in response to activation of Ras-coupled receptors may utilize Raf protein that is already present at the membrane.
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Affiliation(s)
- Mirko Hekman
- Institut fuer Medizinische Strahlenkunde und Zellforschung (MSZ), University of Wuerzburg, 97078 Wuerzburg, Germany
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16
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Levy D, Chami M, Rigaud JL. Two-dimensional crystallization of membrane proteins: the lipid layer strategy. FEBS Lett 2001; 504:187-93. [PMID: 11532452 DOI: 10.1016/s0014-5793(01)02748-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Due to the difficulty to crystallize membrane proteins, there is a considerable interest to intensify research topics aimed at developing new methods of crystallization. In this context, the lipid layer crystallization at the air/water interface, used so far for soluble proteins, has been recently adapted successfully to produce two-dimensional (2D) crystals of membrane proteins, amenable to structural analysis by electron crystallography. Besides to represent a new alternative strategy, this approach gains the advantage to decrease significantly the amount of material needed in incubation trials, thus opening the field of crystallization to those membrane proteins difficult to surexpress and/or purify. The systematic studies that have been performed on different classes of membrane proteins are reviewed and the physico-chemical processes that lead to the production of 2D crystals are addressed. The different drawbacks, advantages and perspectives of this new strategy for providing structural information on membrane proteins are discussed.
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Affiliation(s)
- D Levy
- Institut Curie, Section de Recherche, UMR-CNRS 168 and LRC-CEA 8, 11 Rue Pierre et Marie Curie, 75231 Cedex 05, Paris, France
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17
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Lu Y, Xia X, Sui S. The interaction of trichosanthin with supported phospholipid membranes studied by surface plasmon resonance. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1512:308-16. [PMID: 11406108 DOI: 10.1016/s0005-2736(01)00334-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Trichosanthin (TCS) is a toxic protein isolated from a Chinese herbal medicine, the root tuber of Trichosanthes kirilowii Maximowicz of the Curcurbitaceae family. It is now used in China to terminate early and mid-trimester pregnancies. The ribosome inactivating property is thought to be account for its toxicity; it can inactivate the eukaryotic ribosome through its RNA N-glycosidase activity. The interactions of TCS with biological membrane is thought to be essential for its physiological effect, for it must get across the membrane before it can enter the cytoplasm and exert its RIP function. In the present work, the interaction of TCS with supported phospholipid monolayers is studied by surface plasmon resonance. The results show that electrostatic forces dominate the interaction between TCS and negatively charged phospholipid containing membranes under acid condition and that both the pH value and the ionic strength can influence its binding. It is proposed that, besides electrostatic forces, hydrophobic interaction may also be involved in the binding process.
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Affiliation(s)
- Y Lu
- Department of Biological Sciences and Biotechnology, State-Key Laboratory of Biomembrane, Tsinghua University, 100084, Beijing, PR China
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18
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Mader C, Küpcü S, Sleytr UB, Sára M. S-layer-coated liposomes as a versatile system for entrapping and binding target molecules. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1463:142-50. [PMID: 10631303 DOI: 10.1016/s0005-2736(99)00190-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In the present study, unilamellar liposomes coated with the crystalline bacterial cell surface layer (S-layer) protein of Bacillus stearothermophilus PV72/p2 were used as matrix for defined binding of functional molecules via the avidin- or streptavidin-biotin bridge. The liposomes were composed of dipalmitoyl phosphatidylcholine, cholesterol and hexadecylamine in a molar ratio of 10:5:4 and they had an average size of 180 nm. For introducing specific functions into the S-layer lattice without affecting substances encapsulated within the liposomes, crosslinking and activation reagents had to be identified which did not penetrate the liposomal membrane. Among different reagents, a hydrophilic dialdehyde generated by periodate cleavage of raffinose and a sulfo-succinimide activated dicarboxylic acid were found to be impermeable for the liposomal membrane. Both reagents completely crosslinked the S-layer lattice without interfering with its regular structure. Biotinylation of S-layer-coated liposomes was achieved by coupling p-diazobenzoyl biocytin which preferably reacts with the phenolic residue of tyrosine or with the imidazole ring of histidine. By applying this method, two biotin residues accessible for subsequent avidin binding were introduced per S-layer subunit. As visualized by labeling with biotinylated ferritin, an ordered monomolecular layer of streptavidin was formed on the surface of the S-layer-coated liposomes. As a second model system, biotinylated anti-human IgG was attached via the streptavidin bridge to the biotinylated S-layer-coated liposomes. The biological activity of the bound anti-human IgG was confirmed by ELISA.
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Affiliation(s)
- C Mader
- Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, Universität für Bodenkultur Wien, Gregor-Mendelstr. 33, A-1180, Vienna, Austria
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19
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Chen YH, Xiao Y, Wu W, Wang Q, Luo G, Dierich MP. HIV-2 transmembrane protein gp36 binds to the putative cellular receptor proteins P45 and P62. Immunobiology 2000; 201:317-22. [PMID: 10776788 DOI: 10.1016/s0171-2985(00)80086-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Based on the findings that two cellular proteins of 45 kDa (P45) and 62 kDa (P62) serve as the putative receptor molecules for binding of HIV-1 transmembrane protein gp41 to human T, B lymphocytes and monocytes, we examined whether HIV-2 gp36 and HIV-1 gp41 share the putative receptor proteins P45 and P62. In SPR-assay (SPR: surface plasmon resonance), the recombinant soluble gp36 (rsgp36: Env aa518-678 from clone ROD) like the recombinant soluble gp41 (rsgp41: Env aa539-684 from clone BH10) was binding to P45 and P62. By affinity capillary electrophoresis (ACE)-analysis, formation of stable rsgp36-P45 and rsgp36-P62 complexes were confirmed, and the interactions of rsgp36 with P45 and P62 is quite strong with a fast association rate and a slow dissociation rate. These results indicate that HIV-2 gp36 and HIV-1 gp41 have the common putative cellular receptor proteins P45 and P62, and the binding of gp36 to human lymphocytes and monocytes could be based on the interaction between gp36 and P45 and P62.
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Affiliation(s)
- Y H Chen
- Laboratory of Immunology, School of Life Science and Engineering, Tsinghua University, Beijing, PR, China.
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20
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Sui SF, Sun YT, Mi LZ. Calcium-dependent binding of rabbit C-reactive protein to supported lipid monolayers containing exposed phosphorylcholine group. Biophys J 1999; 76:333-41. [PMID: 9876145 PMCID: PMC1302522 DOI: 10.1016/s0006-3495(99)77200-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The interaction of rabbit C-reactive protein (rCRP) with a supported monolayer containing a phosphorylcholine moiety was studied. Three types of phospholipids were synthesized, each containing a insertion spacer of eight, six, or three atoms between the phosphorylcholine group and hydrophobic tail. By varying the length of the insertion spacer, we can vary the extension of the phosphorylcholine group from the membrane surface. By varying the monolayer composition, we can control the lateral distance between the exposed phosphorylcholine groups. Using the surface plasmon resonance technique (SPR), we demonstrated that the calcium-dependent binding of rCRP to the model membrane is governed not only by the ability of the ligand to access the binding pocket fully (spacer length), but also by lateral hindrance within the two-dimensional plane of the membrane. The value of the apparent binding constant was estimated by theoretical analysis, which is obviously dependent on the composition of the lipid mixture, and a maximum of (9.9 +/- 1.5) x 10(6) M-1 was obtained.
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Affiliation(s)
- S F Sui
- Biophysics Group, State Key Laboratory of Biomembrane, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of
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21
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Surface plasmon resonance biosensors based on biofunctionalized interfaces. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1061-8945(99)80009-9] [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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22
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Wang SX, Cai GP, Sui SF. The insertion of human apolipoprotein H into phospholipid membranes: a monolayer study. Biochem J 1998; 335 ( Pt 2):225-32. [PMID: 9761718 PMCID: PMC1219773 DOI: 10.1042/bj3350225] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Apolipoprotein H (ApoH) is a plasma glycoprotein isolated from human serum. The interactions of ApoH with lipid membrane were reported to be essential for its physiological and pathogenic roles. In this paper we studied the ability of ApoH to insert into phospholipid membranes using the monolayer approach. The results show that ApoH is surface active and can insert into the lipid monolayers. The insertion ability of ApoH is stronger when a higher content of negatively charged lipids is present in the membrane. The acidic-pH and low-ionic-strength conditions will also enhance ApoH insertion, but these factors may not have much influence on the final insertion ability of ApoH, suggesting that, in the mechanism of ApoH insertion, not only electrostatic forces, but also hydrophobic interactions, are evidently involved. Modification by heat inactivation and reduction/alkylation does not change the critical insertion pressure (pic) of ApoH, suggesting a stable domain, maybe a linear sequence motif, but not the native three-dimensional structure of ApoH, is responsible for its insertion. The extent to which insertion of ApoH into phospholipid membranes may facilitate the 'immune cleaning' of plasma liposomes is discussed.
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Affiliation(s)
- S X Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China
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Spaeth K, Brecht A, Gauglitz G. Studies on the Biotin-Avidin Multilayer Adsorption by Spectroscopic Ellipsometry. J Colloid Interface Sci 1997; 196:128-135. [PMID: 9792738 DOI: 10.1006/jcis.1997.5200] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein multilayers were prepared on silica surfaces by up to 20 alternating incubations of a biotin-protein conjugate and polymerized streptavidin. Spectroscopic ellipsometry (350-750 nm) was used to investigate the physical thickness and the dispersion of the protein layer after each incubation step. Both parameters could be determined independently for films formed by 5 to 15 incubations. A single homogeneous protein layer was assumed for evaluation. This determination of layer parameters was limited by high correlation coefficients for less than 5 incubation steps. Deviations from the homogeneous single layer model were found for more than 15 incubation steps. The growth of the layer was reproducible, with a thickness increase of about 18.75 nm per incubation. An almost constant refractive index nD of 1.384 +/- 0.002 was found for the multilayer system. A protein mass deposition of 4.74 ng/mm2 was calculated per incubation step. The protein concentration of the layer was estimated of about 0.27 g/ml. The affinity system investigated is quite simple and may well serve as a prototype system in the characterization of optical and other transducers for affinity reactions. Copyright 1997 Academic Press.
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Affiliation(s)
- K Spaeth
- Institute of Physical Chemistry, University of Tübingen, Auf der Morgenstelle 8, Tübingen, D-72076, Germany
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Chiu W, Avila-Sakar AJ, Schmid MF. Electron crystallography of macromolecular periodic arrays on phospholipid monolayers. ADVANCES IN BIOPHYSICS 1997; 34:161-72. [PMID: 9204133 DOI: 10.1016/s0065-227x(97)89638-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Electron crystallography has the potential of yielding structural information equivalent to x-ray diffraction. The major difficulty has been preparing specimens with the required structural order and size for diffraction and imaging in the electron microscope. 2D crystallization on phospholipid monolayers is capable of fulfilling both of these requirements. Crystals can form as a result of specific interactions with a protein's ligand or an analog, suitably linked to a lipid tail; or on a surface of complementary head-group charge. With such choices, the availability of a suitable lipid is limited only by synthetic chemistry. Ultimately, it is the quality and regularity of the protein-protein interactions that determine the crystalline order, as it is with any protein crystal. In the case of streptavidin, the monolayer crystal diffracts beyond 2.5 A. A 3 A projection map reconstructed from electron diffraction amplitudes and phases from images shows density which can be interpreted as beta-sheets and clusters of side chains. It remains to be shown that the monolayer crystals are flat and diffract as well at high tilt angle as untilted. Technological issues such as charging must be resolved. With parallel advances in data collection and processing, electron crystallography of monolayer macromolecular crystals will eventually take its place beside x-ray crystallography and NMR as a routine and efficient structural technique.
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Affiliation(s)
- W Chiu
- W.M. Keck Center for Computational Biology, Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030, USA
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