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Dubovskii PV, Utkin YN. Specific Amino Acid Residues in the Three Loops of Snake Cytotoxins Determine Their Membrane Activity and Provide a Rationale for a New Classification of These Toxins. Toxins (Basel) 2024; 16:262. [PMID: 38922156 PMCID: PMC11209149 DOI: 10.3390/toxins16060262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 06/27/2024] Open
Abstract
Cytotoxins (CTs) are three-finger membrane-active toxins present mainly in cobra venom. Our analysis of the available CT amino acid sequences, literature data on their membrane activity, and conformational equilibria in aqueous solution and detergent micelles allowed us to identify specific amino acid residues which interfere with CT incorporation into membranes. They include Pro9, Ser28, and Asn/Asp45 within the N-terminal, central, and C-terminal loops, respectively. There is a hierarchy in the effect of these residues on membrane activity: Pro9 > Ser28 > Asn/Asp45. Taking into account all the possible combinations of special residues, we propose to divide CTs into eight groups. Group 1 includes toxins containing all of the above residues. Their representatives demonstrated the lowest membrane activity. Group 8 combines CTs that lack these residues. For the toxins from this group, the greatest membrane activity was observed. We predict that when solely membrane activity determines the cytotoxic effects, the activity of CTs from a group with a higher number should exceed that of CTs from a group with a lower number. This classification is supported by the available data on the cytotoxicity and membranotropic properties of CTs. We hypothesize that the special amino acid residues within the loops of the CT molecule may indicate their involvement in the interaction with non-lipid targets.
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Affiliation(s)
- Peter V. Dubovskii
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Str., 117997 Moscow, Russia;
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2
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Chang CK, Kao MC, Lan CY. Antimicrobial Activity of the Peptide LfcinB15 against Candida albicans. J Fungi (Basel) 2021; 7:jof7070519. [PMID: 34209722 PMCID: PMC8306953 DOI: 10.3390/jof7070519] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023] Open
Abstract
Lactoferricin (Lfcin) is an amphipathic, cationic peptide derived from proteolytic cleavage of the N-lobe of lactoferrin (Lf). Lfcin and its derivatives possess broad-spectrum antibacterial and antifungal activities. However, unlike their antibacterial functions, the modes of action of Lfcin and its derivatives against pathogenic fungi are less well understood. In this study, the mechanisms of LfcinB15, a derivative of bovine Lfcin, against Candida albicans were, therefore, extensively investigated. LfcinB15 exhibited inhibitory activity against planktonic cells, biofilm cells, and clinical isolates of C. albicans and non-albicans Candida species. We further demonstrated that LfcinB15 is localized on the cell surface and vacuoles of C. albicans cells. Moreover, LfcinB15 uses several different methods to kill C. albicans, including disturbing the cell membrane, inducing reactive oxygen species (ROS) generation, and causing mitochondrial dysfunction. Finally, the Hog1 and Mkc1 mitogen-activated protein kinases were both activated in C. albicans cells in response to LfcinB15. These findings help us to obtain more insight into the complex mechanisms used by LfcinB15 and other Lfcin-derived peptides to fight fungal pathogens.
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Affiliation(s)
- Che-Kang Chang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
| | - Mou-Chieh Kao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: (M.-C.K.); ; (C.-Y.L.); Tel.: +886-3-5742473 (M.-C.K.); +886-3-5742472 (C.-Y.L.)
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan;
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Correspondence: (M.-C.K.); ; (C.-Y.L.); Tel.: +886-3-5742473 (M.-C.K.); +886-3-5742472 (C.-Y.L.)
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3
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Dyba B, Rudolphi-Szydło E, Barbasz A, Czyżowska A, Hus KK, Petrilla V, Petrillová M, Legáth J, Bocian A. Effects of 3FTx Protein Fraction from Naja ashei Venom on the Model and Native Membranes: Recognition and Implications for the Mechanisms of Toxicity. Molecules 2021; 26:2164. [PMID: 33918763 PMCID: PMC8070352 DOI: 10.3390/molecules26082164] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/27/2021] [Accepted: 04/07/2021] [Indexed: 02/06/2023] Open
Abstract
Three-finger toxins are naturally occurring proteins in Elapidae snake venoms. Nowadays, they are gaining popularity because of their therapeutic potential. On the other hand, these proteins may cause undesirable reactions inside the body's cells. A full assessment of the safety of Naja ashei venom components for human cell application is still unknown. The aim of the study was to determine the effect of the exogenous application of three-finger toxins on the cells of monocytes (U-937) and promyelocytes (HL-60), with particular emphasis on the modification of their membranes under the influence of various doses of 3FTx protein fraction (0-120 ng/mL). The fraction exhibiting the highest proportion of 3FTx proteins after size exclusion chromatography (SEC) separation was used in the experiments. The structural response of cell membranes was described on the basis of single-component and multi-component Langmuir monolayers that mimicked the native membranes. The results show that the mechanism of protein-lipid interactions depends on both the presence of lipid polar parts (especially zwitterionic type of lipids) and the degree of membrane saturation (the greatest-for unsaturated lipids). The biochemical indicators reflecting the tested cells (MDA, LDH, cell survival, induction of inflammation, LD50) proved the results that were obtained for the model.
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Affiliation(s)
- Barbara Dyba
- Department of Biochemistry and Biophysics, Faculty of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084 Cracow, Poland; (B.D.); (E.R.-S.); (A.B.); (A.C.)
| | - Elżbieta Rudolphi-Szydło
- Department of Biochemistry and Biophysics, Faculty of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084 Cracow, Poland; (B.D.); (E.R.-S.); (A.B.); (A.C.)
| | - Anna Barbasz
- Department of Biochemistry and Biophysics, Faculty of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084 Cracow, Poland; (B.D.); (E.R.-S.); (A.B.); (A.C.)
| | - Agnieszka Czyżowska
- Department of Biochemistry and Biophysics, Faculty of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084 Cracow, Poland; (B.D.); (E.R.-S.); (A.B.); (A.C.)
| | - Konrad Kamil Hus
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland; (K.K.H.); (J.L.)
| | - Vladimír Petrilla
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041-81 Košice, Slovakia;
- Zoological Department, Zoological Garden Košice, Široká 31, 040 06 Košice-Kavečany, Slovakia
| | - Monika Petrillová
- Department of General Competencies, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041-81 Kosice, Slovakia;
| | - Jaroslav Legáth
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland; (K.K.H.); (J.L.)
- Department of Pharmacology and Toxicology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041-81 Košice, Slovakia
| | - Aleksandra Bocian
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland; (K.K.H.); (J.L.)
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4
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Luo M, Dommer AC, Schiffer JM, Rez DJ, Mitchell AR, Amaro RE, Grassian VH. Surfactant Charge Modulates Structure and Stability of Lipase-Embedded Monolayers at Marine-Relevant Aerosol Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:9050-9060. [PMID: 31188612 DOI: 10.1021/acs.langmuir.9b00689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lipases, as well as other enzymes, are present and active within the sea surface microlayer (SSML). Upon bubble bursting, lipases partition into sea spray aerosol (SSA) along with surface-active molecules such as lipids. Lipases are likely to be embedded in the lipid monolayer at the SSA surface and thus have the potential to influence SSA interfacial structure and chemistry. Elucidating the structure of the lipid monolayer at SSA interfaces and how this structure is altered upon interaction with a protein system like lipase is of interest, given the importance of how aerosols interact with sunlight, influence cloud formation, and provide surfaces for chemical reactions. Herein, we report an integrated experimental and computational study of Burkholderia cepacia lipase (BCL) embedded in a lipid monolayer and highlight the important role of electrostatic, rather than hydrophobic, interactions as a driver for monolayer stability. Specifically, we combine Langmuir film experiments and molecular dynamics (MD) simulations to examine the detailed interactions between the zwitterionic dipalmitoylphosphatidylcholine (DPPC) monolayer and BCL. Upon insertion of BCL from the underlying subphase into the lipid monolayer, it is shown that BCL permeates and largely disorders the monolayer while strongly interacting with zwitterionic DPPC molecules, as experimentally observed by Langmuir adsorption curves and infrared reflectance absorbance spectroscopy. Explicitly solvated, all-atom MD is then used to provide insights into inter- and intramolecular interactions that drive these observations, with specific attention to the formation of salt bridges or ionic-bonding interactions. We show that after insertion into the DPPC monolayer, lipase is maintained at high surface pressures and in large BCL concentrations by forming a salt-bridge-stabilized lipase-DPPC complex. In comparison, when embedded in an anionic monolayer at low surface pressures, BCL preferentially forms intramolecular salt bridges, reducing its total favorable interactions with the surfactant and partitioning out of the monolayer shortly after injection. Overall, this study shows that the structure and dynamics of lipase-embedded SSA surfaces vary based on surface charge and pressure and that these variations have the potential to differentially modulate the properties of marine aerosols.
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Affiliation(s)
- Man Luo
- Department of Chemistry and Biochemistry , University of California , San Diego , California 92093 , United States
| | - Abigail C Dommer
- Department of Chemistry and Biochemistry , University of California , San Diego , California 92093 , United States
| | - Jamie M Schiffer
- Janssen Pharmaceuticals , 3210 Merryfield Row , San Diego , California 92093 , United States
| | - Donald J Rez
- Department of Chemistry and Biochemistry , University of California , San Diego , California 92093 , United States
| | - Andrew R Mitchell
- Department of Chemistry and Biochemistry , University of California , San Diego , California 92093 , United States
| | - Rommie E Amaro
- Department of Chemistry and Biochemistry , University of California , San Diego , California 92093 , United States
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry , University of California , San Diego , California 92093 , United States
- Scripps Institution of Oceanography , University of California , San Diego , California 92037 , United States
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Muller MP, Jiang T, Sun C, Lihan M, Pant S, Mahinthichaichan P, Trifan A, Tajkhorshid E. Characterization of Lipid-Protein Interactions and Lipid-Mediated Modulation of Membrane Protein Function through Molecular Simulation. Chem Rev 2019; 119:6086-6161. [PMID: 30978005 PMCID: PMC6506392 DOI: 10.1021/acs.chemrev.8b00608] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The cellular membrane constitutes one of the most fundamental compartments of a living cell, where key processes such as selective transport of material and exchange of information between the cell and its environment are mediated by proteins that are closely associated with the membrane. The heterogeneity of lipid composition of biological membranes and the effect of lipid molecules on the structure, dynamics, and function of membrane proteins are now widely recognized. Characterization of these functionally important lipid-protein interactions with experimental techniques is however still prohibitively challenging. Molecular dynamics (MD) simulations offer a powerful complementary approach with sufficient temporal and spatial resolutions to gain atomic-level structural information and energetics on lipid-protein interactions. In this review, we aim to provide a broad survey of MD simulations focusing on exploring lipid-protein interactions and characterizing lipid-modulated protein structure and dynamics that have been successful in providing novel insight into the mechanism of membrane protein function.
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Affiliation(s)
- Melanie P. Muller
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Tao Jiang
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chang Sun
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Muyun Lihan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shashank Pant
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Paween Mahinthichaichan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anda Trifan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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6
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Dubovskii PV, Dubinnyi MA, Volynsky PE, Pustovalova YE, Konshina AG, Utkin YN, Arseniev AS, Efremov RG. Impact of membrane partitioning on the spatial structure of an S-type cobra cytotoxin. J Biomol Struct Dyn 2017; 36:3463-3478. [DOI: 10.1080/07391102.2017.1389662] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Peter V. Dubovskii
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
| | - Maxim A. Dubinnyi
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
| | - Pavel E. Volynsky
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
| | - Yulia E. Pustovalova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
| | - Anastasia G. Konshina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
| | - Alexander S. Arseniev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
- Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region 141700, Russia
| | - Roman G. Efremov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya str., Moscow 117997, Russia
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7
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Suzuki-Matsubara M, Athauda SBP, Suzuki Y, Matsubara K, Moriyama A. Comparison of the primary structures, cytotoxicities, and affinities to phospholipids of five kinds of cytotoxins from the venom of Indian cobra, Naja naja. Comp Biochem Physiol C Toxicol Pharmacol 2016; 179:158-64. [PMID: 26456928 DOI: 10.1016/j.cbpc.2015.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 11/23/2022]
Abstract
The molecular mechanism underlying the hemolytic and cytolytic processes of cobra cytotoxins (CTXs) is not yet fully elucidated. To examine this, we analyzed the amino acid sequences, hemolytic and cytotoxic activities, and affinities to phospholipids of the five major CTXs purified from the venom of Indian cobra, Naja naja. CTX2, CTX7, and CTX8 belonged to S-type, and CTX9 and CTX10 to P-type. Comparisons of CTX7 with CTX8 and CTX9 with CTX10 revealed similar primary structures and hemolytic and cytolytic activities. CTX2, whose primary structure was rather different from the others, showed several times weaker hemolytic and cytolytic biological activities than the others. The comparison of CTX2 with CTX7 suggested the importance of Lys30 in loop II for the strong hemolytic and cytolytic activities of S-type CTXs. Cloning of 12 CTX cDNAs from the Naja naja venom cDNA library revealed that 18 out of 23 substitutions found in CTX cDNAs were nonsynonymous. This clearly indicated the accelerated evolution of CTX genes. Multiple sequence alignment of 51 kinds of CTX cDNAs and calculations of nonsynonymous and synonymous substitutions indicated that the codons coding the three loops' regions, which may interact with the hydrophobic tails of phospholipids, have undergone an accelerated evolution. In contrast, the codons coding for amino acid residues considered to participate in the recognition and binding of the hydrophilic head groups of phospholipids, eight Cys residues, and those likely stabilizing β core structure, were all conserved.
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Affiliation(s)
- Mieko Suzuki-Matsubara
- Graduate School of Natural Sciences, Nagoya City University, Mizuho, Nagoya 467-8501, Japan.
| | - Senarath B P Athauda
- Department of Biochemistry, Faculty of Medicine, Peradeniya University, Peradeniya, Sri Lanka
| | - Yoshiyuki Suzuki
- Graduate School of Natural Sciences, Nagoya City University, Mizuho, Nagoya 467-8501, Japan
| | - Kazumi Matsubara
- Graduate School of Natural Sciences, Nagoya City University, Mizuho, Nagoya 467-8501, Japan
| | - Akihiko Moriyama
- Graduate School of Natural Sciences, Nagoya City University, Mizuho, Nagoya 467-8501, Japan
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8
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Maltsev S, Hudson SM, Sahu ID, Liu L, Lorigan GA. Solid-state NMR (31)P paramagnetic relaxation enhancement membrane protein immersion depth measurements. J Phys Chem B 2014; 118:4370-7. [PMID: 24689497 PMCID: PMC4002136 DOI: 10.1021/jp500267y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/01/2014] [Indexed: 11/29/2022]
Abstract
Paramagnetic relaxation enhancement (PRE) is a widely used approach for measuring long-range distance constraints in biomolecular solution NMR spectroscopy. In this paper, we show that (31)P PRE solid-state NMR spectroscopy can be utilized to determine the immersion depth of spin-labeled membrane peptides and proteins. Changes in the (31)P NMR PRE times coupled with modeling studies can be used to describe the spin-label position/amino acid within the lipid bilayer and the corresponding helical tilt. This method provides valuable insight on protein-lipid interactions and membrane protein structural topology. Solid-state (31)P NMR data on the 23 amino acid α-helical nicotinic acetylcholine receptor nAChR M2δ transmembrane domain model peptide followed predicted behavior of (31)P PRE rates of the phospholipid headgroup as the spin-label moves from the membrane surface toward the center of the membrane. Residue 11 showed the smallest changes in (31)P PRE (center of the membrane), while residue 22 shows the largest (31)P PRE change (near the membrane surface), when compared to the diamagnetic control M2δ sample. This PRE SS-NMR technique can be used as a molecular ruler to measure membrane immersion depth.
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Affiliation(s)
- Sergey Maltsev
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Stephen M. Hudson
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Indra D. Sahu
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Lishan Liu
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
| | - Gary A. Lorigan
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
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9
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Yu HY, Yip BS, Tu CH, Chen HL, Chu HL, Chih YH, Cheng HT, Sue SC, Cheng JW. Correlations between membrane immersion depth, orientation, and salt-resistance of tryptophan-rich antimicrobial peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2720-8. [DOI: 10.1016/j.bbamem.2013.07.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/01/2013] [Accepted: 07/15/2013] [Indexed: 11/29/2022]
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10
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Maftouni N, Amininasab M, Ejtehadi MR, Kowsari F, Dastvan R. Nanomechanical properties of lipid bilayer: Asymmetric modulation of lateral pressure and surface tension due to protein insertion in one leaflet of a bilayer. J Chem Phys 2013; 138:065101. [DOI: 10.1063/1.4776764] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Hung SW, Hsiao PY, Lu MC, Chieng CC. Thermodynamic Investigations Using Molecular Dynamics Simulations with Potential of Mean Force Calculations for Cardiotoxin Protein Adsorption on Mixed Self-Assembled Monolayers. J Phys Chem B 2012; 116:12661-8. [DOI: 10.1021/jp304695w] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Shih-Wei Hung
- Department of Engineering
and
System Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Pai-Yi Hsiao
- Department of Engineering
and
System Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Ming-Chang Lu
- Department
of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Ching-Chang Chieng
- Department of Engineering
and
System Science, National Tsing Hua University, Hsinchu, Taiwan
- Department
of Mechanical and Biomedical
Engineering, City University of Hong Kong, Kowloon, Hong Kong
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12
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Alves CS, Kairys V, Castanho MARB, Fernandes MX. Interaction of antimicrobial peptides, BP100 and pepR, with model membrane systems as explored by brownian dynamics simulations on a coarse-grained model. Biopolymers 2012. [DOI: 10.1002/bip.22075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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13
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Wu PL, Chiu CR, Huang WN, Wu WG. The role of sulfatide lipid domains in the membrane pore-forming activity of cobra cardiotoxin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:1378-85. [PMID: 22387431 DOI: 10.1016/j.bbamem.2012.02.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 01/20/2012] [Accepted: 02/15/2012] [Indexed: 10/28/2022]
Abstract
Cobra CTX A3, the major cardiotoxin (CTX) from Naja atra, is a cytotoxic, basic β-sheet polypeptide that is known to induce a transient membrane leakage of cardiomyocytes through a sulfatide-dependent CTX membrane pore formation and internalization mechanism. The molecular specificity of CTX A3-sulfatide interaction at atomic levels has also been shown by both nuclear magnetic resonance (NMR) and X-ray diffraction techniques to reveal a role of CTX-induced sulfatide conformational changes for CTX A3 binding and dimer formation. In this study, we investigate the role of sulfatide lipid domains in CTX pore formation by various biophysical methods, including fluorescence imaging and atomic force microscopy, and suggest an important role of liquid-disordered (ld) and solid-ordered (so) phase boundary in lipid domains to facilitate the process. Fluorescence spectroscopic studies on the kinetics of membrane leakage and CTX oligomerization further reveal that, although most CTXs can oligomerize on membranes, only a small fraction of CTXs oligomerizations form leakage pores. We therefore suggest that CTX binding at the boundary between the so and so/ld phase coexistence sulfatide lipid domains could form effective pores to significantly enhance the CTX-induced membrane leakage of sulfatide-containing phosphatidylcholine vesicles. The model is consistent with our earlier observations that CTX may penetrate and lyse the bilayers into small aggregates at a lipid/protein molar ratio of about 20 in the ripple P(β)' phase of phosphatidylcholine bilayers and suggest a novel mechanism for the synergistic action of cobra secretary phospholipase A2 and CTXs.
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Affiliation(s)
- Po-Long Wu
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
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14
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Huang WN, Chen YH, Chen CL, Wu W. Surface pressure-dependent interactions of secretory phospholipase A2 with zwitterionic phospholipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7034-7041. [PMID: 21557547 DOI: 10.1021/la200255r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The hydrolytic activity of secretory phospholipase A(2) (PLA(2)) is regulated by many factors, including the physical state of substrate aggregates and the chemical nature of phospholipid molecules. In order to achieve strong binding of PLA(2) on its substrates, many previous works have used anionic lipid dispersion to characterize the orientation and penetration depth of PLA(2) molecules on membrane surfaces. In this study, we applied monolayer technique with controllable surface area to investigate the PLA(2)s of Taiwan cobra venom and bee venom on zwitterionic phophatidylcholine monolayers and demonstrated an optimum hydrolytic activity at a surface pressure of 18 and 24 mN/m, respectively. By combining polarized attenuated total reflection Fourier-transform infrared spectroscopy and monolayer-binding experiments, we found that the amount of membrane-bound PLA(2) decreased markedly as the surface pressure of the monolayer was increased. Interestingly, the insertion area of the PLA(2)s decreased to near zero as the surface pressure increased to the optimum pressure for hydrolytic activity. On the basis of the measured infrared dichroic ratio, the orientation of the PLA(2)s bound to zwitterionic membranes was similar to that observed on a negatively charged membrane and was independent of the surface pressure. Our findings suggest that both PLA(2)s were located on the membrane surface rather than penetrating the membrane bilayer and that the deeply inserted mode is not a favorable condition for the hydrolysis of phospholipids in zwitterionic phospholipid membranes. The results are discussed in terms of the easy access of catalytic water for the PLA(2) activity and the mobilization of its substrate and product to facilitate the catalytic process.
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Affiliation(s)
- Wei-Ning Huang
- Department of Biotechnology, Yuanpei University, Hsinchu, Taiwan.
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15
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Hung SW, Hsiao PY, Chieng CC. Dynamic information for cardiotoxin protein desorption from a methyl-terminated self-assembled monolayer using steered molecular dynamics simulation. J Chem Phys 2011; 134:194705. [DOI: 10.1063/1.3592559] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Su ZY, Wang YT. Coarse-grained molecular dynamics simulations of cobra cytotoxin A3 interactions with a lipid bilayer: penetration of loops into membranes. J Phys Chem B 2010; 115:796-802. [PMID: 21192700 DOI: 10.1021/jp107599v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cobra cytotoxins, which are small three-looped proteins composed of approximately 60 amino acid residues, primarily act by destroying the bilayer membranes of cells and artificial vesicles. However, the molecular mechanism governing this process is not yet completely understood. We used coarse-grained molecular dynamics (CGMD) simulations to study the mechanism underlying the penetration of cardiotoxin A3 (CTX A3), the major toxic component of Naja atra (Chinese cobra) venom, into a hydrated 1-palmitoyl-2-oleoyl-1-sn-3-phosphatidylcholine (POPC) lipid bilayer. We performed CGMD simulations for three different conformations of the cobra cytotoxin-the tail, lying, and harrow conformations. The results of our simulations indicate that two of these, the tail and lying conformations, did not penetrate the bilayer system. Further, for the harrow conformation, loops 2 and 3 played important roles in penetration of CTX A3 into the bilayer system.
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Affiliation(s)
- Zhi-Yuan Su
- The Department of Information Management, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
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17
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Shih-Wei Hung, Pai-Yi Hsiao, Ching-Chang Chieng. Mixed-SAM Surfaces Monitoring CTX-Protein, Part II: Analysis Using Molecular Dynamics Simulations. IEEE Trans Nanobioscience 2010; 9:297-306. [DOI: 10.1109/tnb.2010.2070517] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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18
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Chu S, Maltsev S, Emwas AH, Lorigan GA. Solid-state NMR paramagnetic relaxation enhancement immersion depth studies in phospholipid bilayers. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 207:89-94. [PMID: 20851650 PMCID: PMC2978330 DOI: 10.1016/j.jmr.2010.08.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 08/11/2010] [Accepted: 08/18/2010] [Indexed: 05/20/2023]
Abstract
A new approach for determining the membrane immersion depth of a spin-labeled probe has been developed using paramagnetic relaxation enhancement (PRE) in solid-state NMR spectroscopy. A DOXYL spin label was placed at different sites of 1-palmitoyl-2-stearoyl-sn-glycero-3-phosphocholine (PSPC) phospholipid bilayers as paramagnetic moieties and the resulting enhancements of the longitudinal relaxation (T₁) times of ³¹P nuclei on the surface of the bilayers were measured by a standard inversion recovery pulse sequence. The ³¹P NMR spin-lattice relaxation times decrease steadily as the DOXYL spin label moves closer to the surface as well as the concentration of the spin-labeled lipids increase. The enhanced relaxation vs. the position and concentration of spin-labels indicate that PRE induced by the DOXYL spin label are significant to determine longer distances over the whole range of the membrane depths. When these data were combined with estimated correlation times τ(c), the r⁻⁶-weighted, time-averaged distances between the spin-labels and the ³¹P nuclei on the membrane surface were estimated. The application of using this solid-state NMR PRE approach coupled with site-directed spin labeling (SDSL) may be a powerful method for measuring membrane protein immersion depth.
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Affiliation(s)
- Shidong Chu
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA 45056
| | - Sergey Maltsev
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA 45056
| | - A-H Emwas
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA 45056
| | - Gary A. Lorigan
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA 45056
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Chang JM, Tseng FG, Chieng CC. Mixed-SAM surfaces monitoring CTX-protein part I: Using atomic force microscope measurements. IEEE Trans Nanobioscience 2010; 9:289-96. [PMID: 20840906 DOI: 10.1109/tnb.2010.2070516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Fast and efficient detection of Cobra cardiotoxin (CTX) protein molecules on biochip surfaces is an example of application in biotechnology. One potential application of mixed self assembled monolayers (SAMs) as chip surfaces yield different binding affinities of the CTX proteins, a series of studies on the interaction force between CTX proteins and the mixed SAMs surfaces formed from mixtures of two thiols with the same/different chain lengths and/or with the same/different terminal groups will be investigated. In these dual papers, the mixed SAMs of n-alkinethiol SAMs of different chain lengths are chosen as the first examples of this series due to the simple functions of the mixed SAMs surface structure. Thus, the adhesion force measurements of CTX protein molecules on mixed SAMs of n-alkinethiol SAMs of different chain lengths: 1-decanethiol (C9) and 1-hexanethiol (C5) with different mixing ratios are developed and conducted using atomic force microscope (AFM). There are two major tasks in Part I of the dual papers: the development of the AFM measurements providing reliable information, and selection of the surface with highest binding affinity among this mixed SAMs group. Results indicate that the adhesion forces for CTX protein molecules on mixed SAMs with mixing ratio (χ(C9)) of 0.25, 0.5, 0.75 and 1, are 1.26, 1.8, 1.38, and 1.25 folds respectively, compared with the adhesion force of CTX protein molecules on the C5 surface only. Therefore, the SAM surfaces of χ(C9) = 0.5 is the best choice as a biomaterial sensor of this group of mixed SAMs because the strongest binding force and highest efficiency. Effects of the loading force of the AFM operation, the radius of curvature of the AFM tip, and the AFM tip endurance as well as control experiments were examined to ensure the quantitative determination of adhesion force for AFM measurement. The physical mechanism of protein adsorption on SAM surfaces will be studied and analyzed by molecular dynamics (MD) simulations and will be reported in Part II of the dual papers to compensate the limited information on the interaction taking place at atomic level that experiments cannot provide.
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Affiliation(s)
- Joe-Ming Chang
- Institute of NanoEngineering and Microsystems, National Tsing Hua University, Hsinchu 30034, Taiwan.
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20
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Levtsova OV, Antonov MY, Mordvintsev DY, Utkin YN, Shaitan KV, Kirpichnikov MP. Steered molecular dynamics simulations of cobra cytotoxin interaction with zwitterionic lipid bilayer: no penetration of loop tips into membranes. Comput Biol Chem 2008; 33:29-32. [PMID: 18774341 DOI: 10.1016/j.compbiolchem.2008.07.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Accepted: 07/07/2008] [Indexed: 11/18/2022]
Abstract
Cobra cytotoxins, small proteins of three-fingered toxin family, unspecifically damage membranes in different cells and artificial vesicles. However, the molecular mechanism of this damage is not yet completely understood. We used steered molecular dynamics simulations to study the interaction of cardiotoxin A3 from Naja atra cobra venom with hydrated 1-palmitoyl-2-oleoyl-1-sn-3-phosphatidylcholine (POPC) bilayer. The studied system included one cytotoxin molecule, 64 lipid molecules (32 molecules in each monolayer) and 2500 water molecules. It was found that the toxin interacted with zwitterionic bilayer formed by POPC. During first nanosecond of simulation the toxin molecule was oriented toward membrane surface by loops' basement including cytotoxin regions Cys14-Asn19 and Cys38-Ser46. This orientation was stable enough and was not changed during next 6 ns of simulation. The obtained data suggest that cytotoxin molecule cannot penetrate into membrane composed of zwitterionic lipids without some auxiliary interaction.
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Affiliation(s)
- O V Levtsova
- Department of Biophysics, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
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21
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Lomize AL, Pogozheva ID, Lomize MA, Mosberg HI. The role of hydrophobic interactions in positioning of peripheral proteins in membranes. BMC STRUCTURAL BIOLOGY 2007; 7:44. [PMID: 17603894 PMCID: PMC1934363 DOI: 10.1186/1472-6807-7-44] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 06/29/2007] [Indexed: 02/05/2023]
Abstract
BACKGROUND Three-dimensional (3D) structures of numerous peripheral membrane proteins have been determined. Biological activity, stability, and conformations of these proteins depend on their spatial positions with respect to the lipid bilayer. However, these positions are usually undetermined. RESULTS We report the first large-scale computational study of monotopic/peripheral proteins with known 3D structures. The optimal translational and rotational positions of 476 proteins are determined by minimizing energy of protein transfer from water to the lipid bilayer, which is approximated by a hydrocarbon slab with a decadiene-like polarity and interfacial regions characterized by water-permeation profiles. Predicted membrane-binding sites, protein tilt angles and membrane penetration depths are consistent with spin-labeling, chemical modification, fluorescence, NMR, mutagenesis, and other experimental studies of 53 peripheral proteins and peptides. Experimental membrane binding affinities of peripheral proteins were reproduced in cases that did not involve a helix-coil transition, specific binding of lipids, or a predominantly electrostatic association. Coordinates of all examined peripheral proteins and peptides with the calculated hydrophobic membrane boundaries, subcellular localization, topology, structural classification, and experimental references are available through the Orientations of Proteins in Membranes (OPM) database. CONCLUSION Positions of diverse peripheral proteins and peptides in the lipid bilayer can be accurately predicted using their 3D structures that represent a proper membrane-bound conformation and oligomeric state, and have membrane binding elements present. The success of the implicit solvation model suggests that hydrophobic interactions are usually sufficient to determine the spatial position of a protein in the membrane, even when electrostatic interactions or specific binding of lipids are substantial. Our results demonstrate that most peripheral proteins not only interact with the membrane surface, but penetrate through the interfacial region and reach the hydrocarbon interior, which is consistent with published experimental studies.
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Affiliation(s)
- Andrei L Lomize
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109-1065, USA
| | - Irina D Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109-1065, USA
| | - Mikhail A Lomize
- College of Literature, Science and the Arts, University of Michigan, Ann Arbor, MI 48109-1065, USA
| | - Henry I Mosberg
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109-1065, USA
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22
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Abstract
A recently developed implicit membrane model (IMM1) is supplemented with a Gouy-Chapman term describing counterion-screened electrostatic interactions of a solute with negatively charged membrane lipids. The new model is tested on peptides that bind to anionic membranes. Pentalysine binds just outside the plane of negative charge, whereas Lys-Phe peptides insert their aromatic rings into the hydrophobic core. Melittin and magainin 2 bind more strongly to anionic than to neutral membranes and in both cases insert their hydrophobic residues into the hydrocarbon core. The third domain of Antennapedia homeodomain (penetratin) binds as an alpha-helix in the headgroup region. Cardiotoxin II binds strongly to anionic membranes but marginally to neutral ones. In all cases, the location and configuration of the peptides are consistent with experimental data, and the effective energy changes upon binding compare favorably with experimental binding free energies. The model opens the way to exploring the effect of membrane charge on the location, conformation, and dynamics of a large variety of biologically active peptides on membranes.
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Hung SW, Hwang JK, Tseng F, Chang JM, Chen CC, Chieng CC. Molecular dynamics simulation of the enhancement of cobra cardiotoxin and E6 protein binding on mixed self-assembled monolayer molecules. NANOTECHNOLOGY 2006; 17:S8-S13. [PMID: 21727358 DOI: 10.1088/0957-4484/17/4/002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Molecular dynamics simulations are performed on n-alkinethiol self-assembled monolayers (SAMs) and their mixture on a gold surface so that the orientations of the binding of cobra cardiotoxin and E6 protein molecules can be selected using the mixing ratio of CH3-terminated SAMs with different chain lengths. The simulations suggest that a SAM surface with different mixing ratios may provide a possible platform for aligning protein molecules with a desired orientation and for enhancing the binding energy of the protein on the designed surface.
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Affiliation(s)
- Shih-Wei Hung
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan
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Wang CH, Liu JH, Lee SC, Hsiao CD, Wu WG. Glycosphingolipid-facilitated membrane insertion and internalization of cobra cardiotoxin. The sulfatide.cardiotoxin complex structure in a membrane-like environment suggests a lipid-dependent cell-penetrating mechanism for membrane binding polypeptides. J Biol Chem 2005; 281:656-67. [PMID: 16263708 DOI: 10.1074/jbc.m507880200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cobra cardiotoxins, a family of basic polypeptides having lipid- and heparin-binding capacities similar to the cell-penetrating peptides, induce severe tissue necrosis and systolic heart arrest in snakebite victims. Whereas cardiotoxins are specifically retained on the cell surface via heparan sulfate-mediated processes, their lipid binding ability appears to be responsible, at least in part, for cardiotoxin-induced membrane leakage and cell death. Although the exact role of lipids involved in toxin-mediated cytotoxicity remains largely unknown, monoclonal anti-sulfatide antibody O4 has recently been shown to inhibit the action of CTX A3, the major cardiotoxin from Taiwan cobra venom, on cardiomyocytes by preventing cardiotoxin-induced membrane leakage and CTX A3 internalization into mitochondria. Here, we show that anti-sulfatide acts by blocking the binding of CTX A3 to the sulfatides in the plasma membrane to prevent sulfatide-dependent CTX A3 membrane pore formation and internalization. We also describe the crystal structure of a CTX A3-sulfatide complex in a membrane-like environment at 2.3 angstroms resolution. The unexpected orientation of the sulfatide fatty chains in the structure allows prediction of the mode of toxin insertion into the plasma membrane. CTX A3 recognizes both the headgroup and the ceramide interfacial region of sulfatide to induce a lipid conformational change that may play a key role in CTX A3 oligomerization and cellular internalization. This proposed lipid-mediated toxin translocation mechanism may also shed light on the cellular uptake mechanism of the amphiphilic cell-penetrating peptides known to involve multiple internalization pathways.
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Affiliation(s)
- Chia-Hui Wang
- Department of Life Sciences and Institute of Bioinformatics and Structural Biology, National Tsinghua University, Hsinchu, Taiwan 30013, Republic of China
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25
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Rødland I, Halskau Ø, Martínez A, Holmsen H. alpha-Lactalbumin binding and membrane integrity--effect of charge and degree of unsaturation of glycerophospholipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1717:11-20. [PMID: 16271262 DOI: 10.1016/j.bbamem.2005.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 08/31/2005] [Accepted: 09/01/2005] [Indexed: 02/04/2023]
Abstract
Several studies have shown that the physical state of the phospholipid membrane has an important role in protein-membrane interactions, involving both electrostatic and hydrophobic forces. We have investigated the influence of the interaction of the calcium-depleted, (apo)-conformation of bovine alpha-lactalbumin (BLA) on the integrity of anionic glycerophospholipid vesicles by leakage experiments using fluorescence spectroscopy. The stability of the membranes was also studied by measuring surface tension/molecular area relationships with phospholipid monolayers. We show that the degree of unsaturation of the acyl chains and the proportion of charged phospholipid species in the membranes made of neutral and acidic glycerophospholipids are determinants for the association of BLA with liposomes and for the impermeability of the bilayer. Particularly, tighter packing counteracted interaction with BLA, while unsaturation-leading to looser packing-promoted interaction and leakage of contents. Equimolar mixtures of neutral and acidic glycerophospholipids were more permeable upon protein binding than pure acidic lipids. The effect of lipid structure on BLA-membrane interaction and bilayer integrity may throw new light on the membrane disrupting mechanism of a conformer of human alpha-lactalbumin (HAMLET) that induces death of tumour cells but not of normal cells.
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Affiliation(s)
- Ingunn Rødland
- Department of Biomedicine, Section for Biochemistry and Molecular Biology, University of Bergen, Norway
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26
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Appelt C, Eisenmenger F, Kühne R, Schmieder P, Söderhäll JA. Interaction of the antimicrobial peptide cyclo(RRWWRF) with membranes by molecular dynamics simulations. Biophys J 2005; 89:2296-306. [PMID: 16040748 PMCID: PMC1366731 DOI: 10.1529/biophysj.105.063040] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antimicrobial peptides have gained a lot of interest in recent years due to their potential use as a new generation of antibiotics. It is believed that this type of relatively short, amphipathic, cationic peptide targets the bacterial membrane, and destroys the chemical gradients over the membrane via formation of stable or transient pores. Here we use the NMR structure of cyclo(RRWWRF) in a series of molecular dynamics simulations in membranes at various peptide/lipid ratios. We observe that the NMR structure of the peptide is still stable after 100 ns simulation. At a peptide/lipid ratio of 2:128, the membrane is only a little affected compared to a pure dipalmitoylphosphatidylcholine lipid membrane, but at a ratio of 12:128, the water-lipid interface becomes more fuzzy, the water molecules can reach deeper into the hydrophobic core, and the water penetration free-energy barrier changes. Moreover, we observe that the area per lipid decreases and the deuterium order parameters increase in the presence of the peptide. We suggest that the changes in the hydrophobic core, together with the changes in the headgroups, result in an imbalance of the membrane and that it is thus not an efficient hydrophobic barrier in the presence of the peptides, independent of pore formation.
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Affiliation(s)
- Christian Appelt
- Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
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27
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Ash WL, Zlomislic MR, Oloo EO, Tieleman DP. Computer simulations of membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1666:158-89. [PMID: 15519314 DOI: 10.1016/j.bbamem.2004.04.012] [Citation(s) in RCA: 204] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Accepted: 04/29/2004] [Indexed: 11/30/2022]
Abstract
Computer simulations are rapidly becoming a standard tool to study the structure and dynamics of lipids and membrane proteins. Increasing computer capacity allows unbiased simulations of lipid and membrane-active peptides. With the increasing number of high-resolution structures of membrane proteins, which also enables homology modelling of more structures, a wide range of membrane proteins can now be simulated over time spans that capture essential biological processes. Longer time scales are accessible by special computational methods. We review recent progress in simulations of membrane proteins.
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Affiliation(s)
- Walter L Ash
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary AB, Canada T2N 1N4
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Li L, Storm P, Karlsson OP, Berg S, Wieslander A. Irreversible binding and activity control of the 1,2-diacylglycerol 3-glucosyltransferase from Acholeplasma laidlawii at an anionic lipid bilayer surface. Biochemistry 2003; 42:9677-86. [PMID: 12911309 DOI: 10.1021/bi034360l] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1,2-Diacylglycerol 3-glucosyltransferase is associated with the membrane surface catalyzing the synthesis of the major nonbilayer-prone lipid alpha-monoglucosyl diacylglycerol (MGlcDAG) from 1,2-DAG in the cell wall-less Acholeplasma laidlawii. Phosphatidylglycerol (PG), but not neutral or zwitterionic lipids, seems to be essential for an active conformation and function of the enzyme. Surface plasmon resonance analysis was employed to study association of the enzyme with lipid bilayers. Binding kinetics could be well fitted only to a two-state model, implying also a (second) conformational step. The enzyme bound less efficiently to liposomes containing only zwitterionic lipids, whereas increasing molar fractions of the anionic PG or cardiolipin (CL) strongly promoted binding by improved association (k(a1)), and especially a decreased rate of return (k(d2)) from the second state. This yielded a very low overall dissociation constant (K(D)), corresponding to an essentially irreversible membrane association. Both liposome binding and consecutive activity of the enzyme correlated with the PG concentration. The importance of the electrostatic interactions with anionic lipids was shown by quenching of both binding and activity with increasing NaCl concentrations, and corroborated in vivo for an active enzyme-green fluorescent protein hybrid in Escherichia coli. Nonbilayer-prone lipids substantially enhanced enzyme-liposome binding by promoting a changed conformation (decreasing k(d2)), similar to the anionic lipids, indicating the importance of hydrophobic interactions and a curvature packing stress. For CL and the nonbilayer lipids, effects on enzyme binding and consecutive activity were not correlated, suggesting a separate lipid control of activity. Similar features were recorded with polylysine (cationic) and polyglutamate (anionic) peptides present, but here probably dependent on the selective charge interactions with the enzyme N- and C-domains, respectively. A lipid-dependent conformational change and PG association of the enzyme were verified by circular dichroism, intrinsic tryptophan, and pyrene-probe fluorescence analyses, respectively. It is concluded that an electrostatic association of the enzyme with the membrane surface is accompanied by hydrophobic interactions and a conformational change. However, specific lipids, the curvature packing stress, and proteins or small molecules bound to the enzyme can modulate the activity of the bound A. laidlawii MGlcDAG synthase.
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Affiliation(s)
- Lu Li
- Department of Biochemistry, Umeå University, Umeå, Sweden
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