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Reis PVM, Lima VM, Souza KR, Cardoso GA, Melo-Braga MN, Santos DM, Verly RM, Pimenta AMC, Dos Santos VL, de Lima ME. Synthetic Peptides Derived From Lycosa Erythrognatha Venom: Interaction With Phospholipid Membranes and Activity Against Resistant Bacteria. Front Mol Biosci 2021; 8:680940. [PMID: 34169094 PMCID: PMC8217815 DOI: 10.3389/fmolb.2021.680940] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/25/2021] [Indexed: 11/13/2022] Open
Abstract
Superbugs are a public health problem, increasing the need of new drugs and strategies to combat them. Our group has previously identified LyeTxI, an antimicrobial peptide isolated from Lycosa erythrognatha spider venom. From LyeTxI, we synthesized and characterized a derived peptide named LyeTxI-b, which has shown significant in vitro and in vivo activity. In this work, we elucidate the interaction of LyeTxI-b with artificial membranes as well as its effects on resistant strains of bacteria in planktonic conditions or biofilms. Isothermal titration calorimetry revealed that LyeTxI-b interacts more rapidly and with higher intensity with artificial vesicles, showing higher affinity to anionic vesicles, when compared to synthetic LyeTxI. In calcein experiments, LyeTxI-b caused greater levels of vesicle cleavage. Both peptides showed antibacterial activity at concentrations of μmol L−1 against 12 different clinically isolated strains, in planktonic conditions, in a concentration-dependent manner. Furthermore, both peptides elicited a dose-dependent production of reactive oxygen species in methicillin-resistant Staphylococcus aureus. In S. aureus biofilm assay, LyeTxI-b was more potent than LyeTxI. However, none of these peptides reduced Escherichia coli biofilms. Our results show LyeTxI-b as a promising drug against clinically resistant strains, being a template for developing new antibiotics.
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Affiliation(s)
- Pablo V M Reis
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo (USP), São Paulo, Brazil.,Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Vinícius M Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Kelton R Souza
- Departamento de Química, FACET, Universidade Federal dos Vales do Jequitinhonha e Mucuri - Campus JK, Diamantina, Brazil
| | - Gabriele A Cardoso
- Departamento de Química, FACET, Universidade Federal dos Vales do Jequitinhonha e Mucuri - Campus JK, Diamantina, Brazil
| | - Marcella N Melo-Braga
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Daniel M Santos
- Departamento de Bioquímica e Biologia Molecular, Campos Centro Oeste. Universidade Federal de São João Del-Rei, Diamantina, Brazil
| | - Rodrigo M Verly
- Departamento de Química, FACET, Universidade Federal dos Vales do Jequitinhonha e Mucuri - Campus JK, Diamantina, Brazil
| | - Adriano M C Pimenta
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Vera Lúcia Dos Santos
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Maria Elena de Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.,Faculdade Santa Casa de Belo Horizonte, Programa de Pós-Graduação em Medicina - Biomedicina, Belo Horizonte, Brazil
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Figueira TN, Domingues MM, Illien F, Cadima-Couto I, Todorovski T, Andreu D, Sagan S, Castanho MARB, Walrant A, Veiga AS. Enfuvirtide-Protoporphyrin IX Dual-Loaded Liposomes: In Vitro Evidence of Synergy against HIV-1 Entry into Cells. ACS Infect Dis 2020; 6:224-236. [PMID: 31855415 DOI: 10.1021/acsinfecdis.9b00285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We have developed a nanocarrier consisting of large unilamellar vesicles (LUVs) for combined delivery of two human immunodeficiency virus type 1 (HIV-1) entry inhibitors, enfuvirtide (ENF) and protoporphyrin IX (PPIX). The intrinsic lipophilicity of ENF and PPIX, a fusion inhibitor and an attachment inhibitor, respectively, leads to their spontaneous incorporation into the lipid bilayer of the LUVs nanocarrier. Both entry inhibitors partition significantly toward LUVs composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and a 9:1 mixture of POPC:1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DPPE-PEG2000), representative of conventional and immune-evasive drug delivery formulations, respectively. These colocalize in the core of lipid membranes. Dual-loaded nanocarriers are monodispersed and retain the size distribution, thermotropic behavior, and surface charge of the unloaded form. Combination of the two entry inhibitors in the nanocarrier resulted in improved synergy against HIV-1 entry compared to combination in free form, strongly when immune-evasive formulations are used. We propose that the improved action of the entry inhibitors when loaded into the nanocarriers results from their slow release at the site of viral entry. Overall, liposomes remain largely unexplored platforms for combination of viral entry inhibitors, with potential for improvement of current antiretroviral therapy drug safety and application. Our work calls for a reappraisal of the potential of entry inhibitor combinations and delivery for clinical use in antiretroviral therapy.
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Affiliation(s)
- Tiago N. Figueira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Marco M. Domingues
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Françoise Illien
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France
| | - Iris Cadima-Couto
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Toni Todorovski
- Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - David Andreu
- Department of Experimental and Health Science, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Sandrine Sagan
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France
| | - Miguel A. R. B. Castanho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Astrid Walrant
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France
| | - Ana Salomé Veiga
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
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Gomes B, Sanna G, Madeddu S, Hollmann A, Santos NC. Combining 25-Hydroxycholesterol with an HIV Fusion Inhibitor Peptide: Interaction with Biomembrane Model Systems and Human Blood Cells. ACS Infect Dis 2019; 5:582-591. [PMID: 30816690 DOI: 10.1021/acsinfecdis.8b00321] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The fusion between the viral and the target cell membrane is a crucial step in the life cycle of enveloped viruses. The blocking of this process is a well-known therapeutic approach that led to the development of the fusion inhibitor peptide enfuvirtide, clinically used against human immunodeficiency virus (HIV) type 1. Despite this significant advance on viral treatment, the appearance of resistance has limited its clinical use. Such a limitation has led to the development of other fusion inhibitor peptides, such as C34, that present the same structural domain as enfuvirtide (heptad repeat sequence) but have different functional domains (pocket-binding domain in the case of C34 and lipid-binding domain in the case of enfuvirtide). Recently, the antiviral properties of 25-hydroxycholesterol were demonstrated, which boosted the interest in this oxysterol. The combination of two distinct antiviral molecules, C34 and 25-hydroxycholesterol, may help to suppress the emergence of resistant viruses. In this work, we characterized the interaction of the C34-25-hydroxycholesterol conjugate with biomembrane model systems and human blood cells. Lipid vesicles and monolayers with defined lipid compositions were used as biomembrane model systems. The conjugate interacts preferentially with membranes rich in sphingomyelin (a lipid enriched in lipid rafts) and presents a poor partition to membranes composed solely of phosphatidylcholine and cholesterol. We hypothesize that cholesterol causes a repulsive effect that is overcome in the presence of sphingomyelin. Importantly, the peptide shows a preference for human peripheral blood mononuclear cells relative to erythrocytes, which shows its potential to target CD4+ cells. Antiviral activity results against different wild-type and drug-resistant HIV strains further demonstrated the potential of C34-HC as a good candidate for future studies.
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Affiliation(s)
- Bárbara Gomes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Giusepinna Sanna
- Department of Biomedical Sciences, Section of Microbiology and Virology, University of Cagliary, Cagliari 09123, Italy
| | - Silvia Madeddu
- Department of Biomedical Sciences, Section of Microbiology and Virology, University of Cagliary, Cagliari 09123, Italy
| | - Axel Hollmann
- Laboratory of Bioactive Compounds, CIBAAL−University of Santiago del Estero and CONICET, Santiago del Estero, Argentina
- Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, University of Quilmes, Bernal B1876BXD, Argentina
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
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Mandaliti W, Nepravishta R, Pica F, Vallebona PS, Garaci E, Paci M. Potential mechanism of thymosin-α1-membrane interactions leading to pleiotropy: experimental evidence and hypotheses. Expert Opin Biol Ther 2018; 18:33-42. [DOI: 10.1080/14712598.2018.1456527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Walter Mandaliti
- Department of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Rome, Italy
| | - Ridvan Nepravishta
- Department of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Rome, Italy
- School of Pharmacy, East Anglia University, Norwich, UK
| | - Francesca Pica
- Department of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Rome, Italy
| | | | - Enrico Garaci
- San Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, Rome, Italy
| | - Maurizio Paci
- Department of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Rome, Italy
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5
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Interaction of semiochemicals with model lipid membranes: A biophysical approach. Colloids Surf B Biointerfaces 2018; 161:413-419. [PMID: 29121614 DOI: 10.1016/j.colsurfb.2017.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/18/2017] [Accepted: 11/01/2017] [Indexed: 12/20/2022]
Abstract
Unravelling the chemical language of insects has been the subject of intense research in the field of chemical ecology for the past five decades. Insect communication is mainly based on chemosensation due to the small body size of insects, which limits their ability to produce or perceive auditory and visual signals, especially over large distances. Chemicals involved in insect communication are called semiochemicals. These volatiles and semivolatiles compounds allow to Insects to find a mate, besides the oviposition site in reproduction and food sources. Actually, insect olfaction mechanism is subject to study, but systematic analyses of the role of neural membranes are scarce. In the present work we evaluated the interactions of α-pinene, benzaldehyde, eugenol, and grandlure, among others, with a lipid membrane model using surface pressure experiments and Monte Carlo computational analysis. This allowed us to propose a plausible membranotropic mechanism of interaction between semiochemicals and insect neural membrane.
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Mavioso ICVC, de Andrade VCR, Palace Carvalho AJ, Martins do Canto AMT. Molecular dynamics simulations of T-2410 and T-2429 HIV fusion inhibitors interacting with model membranes: Insight into peptide behavior, structure and dynamics. Biophys Chem 2017; 228:69-80. [PMID: 28711675 DOI: 10.1016/j.bpc.2017.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 06/24/2017] [Accepted: 06/26/2017] [Indexed: 11/17/2022]
Abstract
T-2410 and T-2429 are HIV fusion inhibitor peptides (FI) designed to present a higher efficiency even against HIV strains that developed resistance against other FIs. Similar peptides were shown to interact with model membranes both in the liquid disordered phase and in the liquid ordered state. Those results indicated that such interaction is important to function and could be correlated with their effectiveness. Extensive molecular dynamics simulations were carried out to investigate the interactions between both T-2410 and T-2429 with bilayers of pure 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) and a mixture of POPC/cholesterol (Chol) (1:1). It was observed that both peptides interact strongly with both membrane systems, especially with the POPC/Chol systems, where these peptides show the highest number of H-bonds observed so far. T-2410 and T-2429 showed higher extent of interaction with bilayers when compared to T-20 or T-1249 in previous studies. This is most notable in POPC/Chol membranes where, although able to form H-bonds with Chol, they do so to a lesser extent than T-1249 does, the latter being the only FI peptide so far that was observed to form H-bonds with Chol. This behavior suggests that interaction of FI peptides with rigid Chol rich membranes may not be as dependent from peptide/Chol H-bond formation as previous results of T-1249 behavior led to believe. As in other similar peptides, the higher ability to interact with membranes shown by T-2410 and T2429 is probably correlated with its higher inhibitory efficiency.
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Affiliation(s)
- I C V C Mavioso
- Departamento de Química, Escola de Ciências e Tecnologia, Universidade de Évora, Rua Romão Ramalho 59, 7000-671 Évora, Portugal
| | - V C R de Andrade
- Departamento de Química, Escola de Ciências e Tecnologia, Universidade de Évora, Rua Romão Ramalho 59, 7000-671 Évora, Portugal
| | - A J Palace Carvalho
- Departamento de Química, Escola de Ciências e Tecnologia, Universidade de Évora, Rua Romão Ramalho 59, 7000-671 Évora, Portugal; Centro de Química de Évora, IIFA, Universidade de Évora, Rua Romão Ramalho 59, 7000-671 Évora, Portugal
| | - A M T Martins do Canto
- Departamento de Química, Escola de Ciências e Tecnologia, Universidade de Évora, Rua Romão Ramalho 59, 7000-671 Évora, Portugal; Centro de Química de Évora, IIFA, Universidade de Évora, Rua Romão Ramalho 59, 7000-671 Évora, Portugal.
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7
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Cao P, Dou G, Cheng Y, Che J. The improved efficacy of Sifuvirtide compared with enfuvirtide might be related to its selectivity for the rigid biomembrane, as determined through surface plasmon resonance. PLoS One 2017; 12:e0171567. [PMID: 28207776 PMCID: PMC5312942 DOI: 10.1371/journal.pone.0171567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 01/22/2017] [Indexed: 11/19/2022] Open
Abstract
Most mechanistic studies on human immunodeficiency virus (HIV) peptide fusion inhibitors have focused on the interactions between fusion inhibitors and viral envelope proteins. However, the interactions of fusion inhibitors with viral membranes are also essential for the efficacy of these drugs. Here, we utilized surface plasmon resonance (SPR) technology to study the interactions between the HIV fusion inhibitor peptides sifuvirtide and enfuvirtide and biomembrane models. Sifuvirtide presented selectivity toward biomembrane models composed of saturated dipalmitoylphosphatidylcholine (DPPC) (32-fold higher compared with unsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine [POPC]) and sphingomyelin (SM) (31-fold higher compared with POPC), which are rigid compositions enriched in the HIV viral membrane. In contrast, enfuvirtide showed no significant selectively toward these rigid membrane models. Furthermore, the bindings of sifuvirtide and enfuvirtide to SM bilayers were markedly higher than those to monolayers (14-fold and 23-fold, respectively), indicating that the inner leaflet influences the binding of these drugs to SM bilayers. No obvious differences were noted in the bindings of either peptide to the other mono- and bilayer models tested, illustrating that both peptides interact with these membranes through surface-binding. The bindings of the inhibitor peptides to biomembranes were found to be driven predominantly by hydrophobic interactions rather than electrostatic interactions, as determined by comparing their affinities to those of positively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine (EPC) to zwitterionic membrane models. The improved efficiency of sifuvirtide relative to enfuvirtide might be related to its ability to adsorb on rigid lipidic areas, such as the viral envelope and lipid rafts, which results in an increased sifuvirtide concentration at the fusion site.
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Affiliation(s)
- Ping Cao
- Laboratory of Hematological Pharmacology, State Key Laboratory of Drug Metabolism, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China
- Beijing Institute of Microbiology and Epidemiology, Beijing, People's Republic of China
| | - Guifang Dou
- Laboratory of Hematological Pharmacology, State Key Laboratory of Drug Metabolism, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China
| | - Yuanguo Cheng
- Beijing Institute of Microbiology and Epidemiology, Beijing, People's Republic of China
- * E-mail: (YC); (JC)
| | - Jinjing Che
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, People's Republic of China
- * E-mail: (YC); (JC)
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In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence. J Virol 2016; 91:JVI.01554-16. [PMID: 27733647 DOI: 10.1128/jvi.01554-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/04/2016] [Indexed: 01/08/2023] Open
Abstract
Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the prefusion F undergoes a structural transition, extending and inserting into the target cell membrane and then refolding into a postfusion structure that fuses the viral and cell membranes. By interfering with this structural transition of F, peptides derived from the heptad repeat (HR) regions of F can inhibit MV infection at the entry stage. In previous work, we have generated potent MV fusion inhibitors by dimerizing the F-derived peptides and conjugating them to cholesterol. We have shown that prophylactic intranasal administration of our lead fusion inhibitor efficiently protects from MV infection in vivo We show here that peptides tagged with lipophilic moieties self-assemble into nanoparticles until they reach the target cells, where they are integrated into cell membranes. The self-assembly feature enhances biodistribution and the half-life of the peptides, while integration into the target cell membrane increases fusion inhibitor potency. These factors together modulate in vivo efficacy. The results suggest a new framework for developing effective fusion inhibitory peptides. IMPORTANCE Measles virus (MV) infection causes an acute illness that may be associated with infection of the central nervous system (CNS) and severe neurological disease. No specific treatment is available. We have shown that fusion-inhibitory peptides delivered intranasally provide effective prophylaxis against MV infection. We show here that specific biophysical properties regulate the in vivo efficacy of MV F-derived peptides.
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Nepravishta R, Mandaliti W, Vallebona PS, Pica F, Garaci E, Paci M. Mechanism of Action of Thymosinα1: Does It Interact with Membrane by Recognition of Exposed Phosphatidylserine on Cell Surface? A Structural Approach. VITAMINS AND HORMONES 2016; 102:101-19. [PMID: 27450732 DOI: 10.1016/bs.vh.2016.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thymosinα1 is a peptidic hormone with pleiotropic activity, which is used in the therapy of several diseases. It is unstructured in water solution and interacts with negative regions of micelles and vesicles assuming two tracts of helical conformation with a structural flexible break in between. The studies of the interaction of Thymosinα1 with micelles of mixed dipalmitoylphosphatidylcholine and sodium dodecylsulfate and vesicles with mixed dipalmitoylphosphatidylcholine/dipalmitoylphosphatidylserine, the latter the negative component of the membranes, by (1)H and natural abundance (15)N NMR are herewith reported, reviewed, and discussed. The results indicate that the preferred interactions are those where the surface is negatively charged due to sodium dodecylsulfate or due to the presence of dipalmitoylphosphatidylserine exposed on the surface. In fact the unbalance of dipalmitoylphosphatidylserine on the cellular surface is an important phenomenon present in pathological conditions of cells. Moreover, the direct interaction of Thymosinα1 with K562 cells presenting an overexposure of phosphatidylserine as a consequence of resveratrol-induced apoptosis was carried out.
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Affiliation(s)
- R Nepravishta
- University of Rome "Tor Vergata", Rome, Italy; Faculty of Pharmacy Catholic University "Our Lady of Good Counsel", Tirane, Albania
| | - W Mandaliti
- University of Rome "Tor Vergata", Rome, Italy
| | | | - F Pica
- University of Rome "Tor Vergata", Rome, Italy
| | - E Garaci
- University of Rome "Tor Vergata", Rome, Italy; San Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, Rome, Italy
| | - M Paci
- University of Rome "Tor Vergata", Rome, Italy.
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Abstract
BACKGROUND T20 (enfuvirtide) is the first approved HIV entry inhibitor and currently the only viral fusion inhibitor, but its low efficacy and genetic barrier to resistance significantly limit its application, calling for a next-generation drug. DESIGN On the basis of the M-T hook structure, we recently developed a short-peptide named HP23, which mainly targets the deep pocket site of gp41 and possesses highly potent antiviral activity. To improve the pharmaceutical properties of a peptide-based inhibitor, we modified HP23 by different classes of lipids including fatty acid, cholesterol, and sphingolipids. To avoid the potential problem of oxidation, the methionine residue in the M-T hook sequence of HP23 was replaced with leucine. METHODS Peptides were synthesized and their anti-HIV activity and biophysical properties were determined. RESULTS A group of lipopeptides were generated with greatly improved anti-HIV activity. Promisingly, a fatty acid-conjugated lipopeptide named LP-11 showed potent and broad inhibitory activity against diverse primary HIV-1 isolates and clinically drug-resistant mutants, and it had dramatically increased ex-vivo antiviral activity and extended half-life. Also, LP-11 displayed highly enhanced α-helicity and thermal stability, and it was physically stable under high temperature and humidity. CONCLUSION LP-11 has high potentials for clinical development and it can serve as an ideal tool for exploring the mechanisms of HIV-1 fusion and inhibition.
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11
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Mandaliti W, Nepravishta R, Sinibaldi Vallebona P, Pica F, Garaci E, Paci M. Thymosin α1 Interacts with Exposed Phosphatidylserine in Membrane Models and in Cells and Uses Serum Albumin as a Carrier. Biochemistry 2016; 55:1462-72. [DOI: 10.1021/acs.biochem.5b01345] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Walter Mandaliti
- Department
of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Ridvan Nepravishta
- Department
of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
- Department
of Chemical Pharmaceutical and Biomolecular Technologies, Faculty of Pharmacy Catholic University “Our Lady of Good Counsel”, Rr. D.
Hoxha, Tirane, Albania
| | - Paola Sinibaldi Vallebona
- Department
of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Via Montpellier 1, 00133 Rome, Italy
| | - Francesca Pica
- Department
of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Via Montpellier 1, 00133 Rome, Italy
| | - Enrico Garaci
- Department
of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Via Montpellier 1, 00133 Rome, Italy
- San
Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, 00163 Rome, Italy
| | - Maurizio Paci
- Department
of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
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Membrane-Active Sequences within gp41 Membrane Proximal External Region (MPER) Modulate MPER-Containing Peptidyl Fusion Inhibitor Activity and the Biosynthesis of HIV-1 Structural Proteins. PLoS One 2015; 10:e0134851. [PMID: 26230322 PMCID: PMC4521866 DOI: 10.1371/journal.pone.0134851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/14/2015] [Indexed: 12/04/2022] Open
Abstract
The membrane proximal external region (MPER) is a highly conserved membrane-active region located at the juxtamembrane positions within class I viral fusion glycoproteins and essential for membrane fusion events during viral entry. The MPER in the human immunodeficiency virus type I (HIV-1) envelope protein (Env) interacts with the lipid bilayers through a cluster of tryptophan (Trp) residues and a C-terminal cholesterol-interacting motif. The inclusion of the MPER N-terminal sequence contributes to the membrane reactivity and anti-viral efficacy of the first two anti-HIV peptidyl fusion inhibitors T20 and T1249. As a type I transmembrane protein, Env also interacts with the cellular membranes during its biosynthesis and trafficking. Here we investigated the roles of MPER membrane-active sequences during both viral entry and assembly, specifically, their roles in the design of peptidyl fusion inhibitors and the biosynthesis of viral structural proteins. We found that elimination of the membrane-active elements in MPER peptides, namely, penta Trp→alanine (Ala) substitutions and the disruption of the C-terminal cholesterol-interacting motif through deletion inhibited the anti-viral effect against the pseudotyped HIV-1. Furthermore, as compared to C-terminal dimerization, N-terminal dimerization of MPER peptides and N-terminal extension with five helix-forming residues enhanced their anti-viral efficacy substantially. The secondary structure study revealed that the penta-Trp→Ala substitutions also increased the helical content in the MPER sequence, which prompted us to study the biological relevance of such mutations in pre-fusion Env. We observed that Ala mutations of Trp664, Trp668 and Trp670 in MPER moderately lowered the intracellular and intraviral contents of Env while significantly elevating the content of another viral structural protein, p55/Gag and its derivative p24/capsid. The data suggest a role of the gp41 MPER in the membrane-reactive events during both viral entry and budding, and provide insights into the future development of anti-viral therapeutics.
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Figueira TN, Veiga AS, Castanho MA. The interaction of antibodies with lipid membranes unraveled by fluorescence methodologies. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.02.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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HIV-1 entry in SupT1-R5, CEM-ss, and primary CD4+ T cells occurs at the plasma membrane and does not require endocytosis. J Virol 2014; 88:13956-70. [PMID: 25253335 DOI: 10.1128/jvi.01543-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
UNLABELLED Cytoplasmic entry of HIV-1 requires binding of the viral glycoproteins to the cellular receptor and coreceptor, leading to fusion of viral and cellular membranes. Early studies suggested that productive HIV-1 infection occurs by direct fusion at the plasma membrane. Endocytotic uptake of HIV-1 was frequently observed but was considered to constitute an unspecific dead-end pathway. More recent evidence suggested that endocytosis contributes to productive HIV-1 entry and may even represent the predominant or exclusive route of infection. We have analyzed HIV-1 binding, endocytosis, cytoplasmic entry, and infection in T-cell lines and in primary CD4(+) T cells. Efficient cell binding and endocytosis required viral glycoproteins and CD4, but not the coreceptor. The contribution of endocytosis to cytoplasmic entry and infection was assessed by two strategies: (i) expression of dominant negative dynamin-2 was measured and was found to efficiently block HIV-1 endocytosis but to not affect fusion or productive infection. (ii) Making use of the fact that HIV-1 fusion is blocked at temperatures below 23 °C, cells were incubated with HIV-1 at 22 °C for various times, and endocytosis was quantified by parallel analysis of transferrin and fluorescent HIV-1 uptake. Subsequently, entry at the plasma membrane was blocked by high concentrations of the peptidic fusion inhibitor T-20, which does not reach previously endocytosed particles. HIV-1 infection was scored after cells were shifted to 37 °C in the presence of T-20. These experiments revealed that productive HIV-1 entry occurs predominantly at the plasma membrane in SupT1-R5, CEM-ss, and primary CD4(+) T cells, with little, if any, contribution coming from endocytosed virions. IMPORTANCE HIV-1, like all enveloped viruses, reaches the cytoplasm by fusion of the viral and cellular membranes. Many viruses enter the cytoplasm by endosomal uptake and fusion from the endosome, while cell entry can also occur by direct fusion at the plasma membrane in some cases. Conflicting evidence regarding the site of HIV-1 fusion has been reported, with some studies claiming that fusion occurs predominantly at the plasma membrane, while others have suggested predominant or even exclusive fusion from the endosome. We have revisited HIV-1 entry using a T-cell line that exhibits HIV-1 endocytosis dependent on the viral glycoproteins and the cellular CD4 receptor; results with this cell line were confirmed for another T-cell line and primary CD4(+) T cells. Our studies show that fusion and productive entry occur predominantly at the plasma membrane, and we conclude that endocytosis is dispensable for HIV-1 infectivity in these T-cell lines and in primary CD4(+) T cells.
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15
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Augusto MT, Hollmann A, Castanho MARB, Porotto M, Pessi A, Santos NC. Improvement of HIV fusion inhibitor C34 efficacy by membrane anchoring and enhanced exposure. J Antimicrob Chemother 2014; 69:1286-97. [PMID: 24464268 DOI: 10.1093/jac/dkt529] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The aim of the present work was to evaluate the interaction of two new HIV fusion inhibitors {HIVP3 [C34-polyethylene glycol (PEG)₄-cholesterol] and HIVP4 [(C34-PEG₄)₂-cholesterol]} with membrane model systems and human blood cells in order to clarify where and how the fusion inhibitors locate, allowing us to understand their mechanism of action at the molecular level, and which strategies may be followed to increase efficacy. METHODS Lipid vesicles with defined compositions were used for peptide partition and localization studies, based on the intrinsic fluorescence of HIVP3 and HIVP4. Lipid monolayers were employed in surface pressure studies. Finally, human erythrocytes and peripheral blood mononuclear cells (PBMCs) isolated from blood samples were used in dipole potential assays. RESULTS Membrane partition, dipole potential and surface pressure assays indicate that the new fusion inhibitors interact preferentially with cholesterol-rich liquid-ordered membranes, mimicking biological membrane microdomains known as lipid rafts. HIVP3 and HIVP4 are able to interact with human erythrocytes and PBMCs to a similar degree as a previously described simpler drug with monomeric C34 and lacking the PEG spacer, C34-cholesterol. However, the pocket-binding domain (PBD) of both HIVP3 and HIVP4 is more exposed to the aqueous environment than in C34-cholesterol. CONCLUSIONS The present data allow us to conclude that more efficient blocking of HIV entry results from the synergism between the membranotropic behaviour and the enhanced exposure of the PBD.
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Affiliation(s)
- Marcelo T Augusto
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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16
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Liu W, Tan J, Mehryar MM, Teng Z, Zeng Y. Peptide HIV fusion inhibitors: modifications and conjugations. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00214h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
HIV fusion inhibitors are a group of virus entry preventing drugs aimed at membrane fusion.
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Affiliation(s)
- Wei Liu
- College of Life Science and Bioengineering
- Beijing University of Technology
- Beijing 100124, China
- State Key Laboratory for Infectious Disease Prevention and Control
- National Institute for Viral disease control and prevention
| | - Jianjun Tan
- College of Life Science and Bioengineering
- Beijing University of Technology
- Beijing 100124, China
| | | | - Zhiping Teng
- State Key Laboratory for Infectious Disease Prevention and Control
- National Institute for Viral disease control and prevention
- Chinese Centre for Disease Control and Prevention
- Beijing 100052, China
| | - Yi Zeng
- College of Life Science and Bioengineering
- Beijing University of Technology
- Beijing 100124, China
- State Key Laboratory for Infectious Disease Prevention and Control
- National Institute for Viral disease control and prevention
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17
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Decoding distinct membrane interactions of HIV-1 fusion inhibitors using a combined atomic force and fluorescence microscopy approach. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1777-85. [DOI: 10.1016/j.bbamem.2013.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 01/01/2013] [Accepted: 03/03/2013] [Indexed: 11/19/2022]
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18
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Martins do Canto AMT, Palace Carvalho AJ, Prates Ramalho JP, Loura LMS. Effect of amphipathic HIV fusion inhibitor peptides on POPC and POPC/cholesterol membrane properties: a molecular simulation study. Int J Mol Sci 2013; 14:14724-43. [PMID: 23860208 PMCID: PMC3742270 DOI: 10.3390/ijms140714724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 06/22/2013] [Accepted: 06/25/2013] [Indexed: 11/16/2022] Open
Abstract
T-20 and T-1249 fusion inhibitor peptides were shown to interact with 1-palmitoyl-2-oleyl-phosphatidylcholine (POPC) (liquid disordered, ld) and POPC/cholesterol (1:1) (POPC/Chol) (liquid ordered, lo) bilayers, and they do so to different extents. Although they both possess a tryptophan-rich domain (TRD), T-20 lacks a pocket binding domain (PBD), which is present in T-1249. It has been postulated that the PBD domain enhances FI interaction with HIV gp41 protein and with model membranes. Interaction of these fusion inhibitor peptides with both the cell membrane and the viral envelope membrane is important for function, i.e., inhibition of the fusion process. We address this problem with a molecular dynamics approach focusing on lipid properties, trying to ascertain the consequences and the differences in the interaction of T-20 and T-1249 with ld and lo model membranes. T-20 and T-1249 interactions with model membranes are shown to have measurable and different effects on bilayer structural and dynamical parameters. T-1249’s adsorption to the membrane surface has generally a stronger influence in the measured parameters. The presence of both binding domains in T-1249 appears to be paramount to its stronger interaction, and is shown to have a definite importance in membrane properties upon peptide adsorption.
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Affiliation(s)
- António M. T. Martins do Canto
- Department of Chemistry, School of Science and Technology, University of Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal; E-Mails: (A.M.T.M.C.); (A.J.P.C.); (J.P.P.R.)
- Centre for Chemistry-Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal
| | - Alfredo J. Palace Carvalho
- Department of Chemistry, School of Science and Technology, University of Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal; E-Mails: (A.M.T.M.C.); (A.J.P.C.); (J.P.P.R.)
- Centre for Chemistry-Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal
| | - João P. Prates Ramalho
- Department of Chemistry, School of Science and Technology, University of Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal; E-Mails: (A.M.T.M.C.); (A.J.P.C.); (J.P.P.R.)
- Centre for Chemistry-Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal
| | - Luís M. S. Loura
- Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
- Centre for Chemistry-Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +351-239-488-485; Fax: +351-239-827-126
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19
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Nomura W, Hashimoto C, Suzuki T, Ohashi N, Fujino M, Murakami T, Yamamoto N, Tamamura H. Multimerized CHR-derived peptides as HIV-1 fusion inhibitors. Bioorg Med Chem 2013; 21:4452-8. [PMID: 23800723 DOI: 10.1016/j.bmc.2013.05.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 05/28/2013] [Accepted: 05/29/2013] [Indexed: 11/24/2022]
Abstract
To date, several HIV-1 fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of an HIV-1 envelope protein gp41 have been discovered. We have shown that a synthetic peptide mimetic of a trimer form of the CHR-derived peptide C34 has potent inhibitory activity against the HIV-1 fusion mechanism, compared to a monomer C34 peptide. The present study revealed that a dimeric form of C34 is evidently structurally critical for fusion inhibitors, and that the activity of multimerized CHR-derived peptides in fusion inhibition is affected by the properties of the unit peptides C34, SC34EK, and T20. The fluorescence-based study suggested that the N36-interactive sites of the C34 trimer, including hydrophobic residues, are exposed outside the trimer and that trimerization of C34 caused a remarkable increase in fusion inhibitory activity. The present results could be useful in the design of fusion inhibitors against viral infections which proceed via membrane fusion with host cells.
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Affiliation(s)
- Wataru Nomura
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo 101-0062, Japan
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20
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Conjugation of cholesterol to HIV-1 fusion inhibitor C34 increases peptide-membrane interactions potentiating its action. PLoS One 2013; 8:e60302. [PMID: 23565220 PMCID: PMC3614957 DOI: 10.1371/journal.pone.0060302] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 02/25/2013] [Indexed: 01/28/2023] Open
Abstract
Recently, the covalent binding of a cholesterol moiety to a classical HIV-1 fusion inhibitor peptide, C34, was shown to potentiate its antiviral activity. Our purpose was to evaluate the interaction of cholesterol-conjugated and native C34 with membrane model systems and human blood cells to understand the effects of this derivatization. Lipid vesicles and monolayers with defined compositions were used as model membranes. C34-cholesterol partitions more to fluid phase membranes that mimic biological membranes. Importantly, there is a preference of the conjugate for liquid ordered membranes, rich in cholesterol and/or sphingomyelin, as observed both from partition and surface pressure studies. In human erythrocytes and peripheral blood mononuclear cells (PBMC), C34-cholesterol significantly decreases the membrane dipole potential. In PBMC, the conjugate was 14- and 115-fold more membranotropic than T-1249 and enfuvirtide, respectively. C34 or cholesterol alone did not show significant membrane activity. The enhanced interaction of C34-cholesterol with biological membranes correlates with its higher antiviral potency. Higher partitions for lipid-raft like compositions direct the drug to the receptor-rich domains where membrane fusion is likely to occur. This intermediary membrane binding step may facilitate the drug delivery to gp41 in its pre-fusion state.
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21
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Cai L, Gochin M, Liu K. Biochemistry and biophysics of HIV-1 gp41 - membrane interactions and implications for HIV-1 envelope protein mediated viral-cell fusion and fusion inhibitor design. Curr Top Med Chem 2012; 11:2959-84. [PMID: 22044229 DOI: 10.2174/156802611798808497] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 03/16/2011] [Accepted: 12/01/2011] [Indexed: 11/22/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1), the pathogen of acquired immunodeficiency syndrome (AIDS), causes ~2 millions death every year and still defies an effective vaccine. HIV-1 infects host cells through envelope protein - mediated virus-cell fusion. The transmembrane subunit of envelope protein, gp41, is the molecular machinery which facilitates fusion. Its ectodomain contains several distinguishing functional domains, fusion peptide (FP), Nterminal heptad repeat (NHR), C-terminal heptad repeat (CHR) and membrane proximal extracellular region (MPER). During the fusion process, FP inserts into the host cell membrane, and an extended gp41 prehairpin conformation bridges the viral and cell membranes through MPER and FP respectively. Subsequent conformational change of the unstable prehairpin results in a coiled-coil 6-helix bundle (6HB) structure formed between NHR and CHR. The energetics of 6HB formation drives membrane apposition and fusion. Drugs targeting gp41 functional domains to prevent 6HB formation inhibit HIV-1 infection. T20 (enfuvirtide, Fuzeon) was approved by the US FDA in 2003 as the first fusion inhibitor. It is a 36-residue peptide from the gp41 CHR, and it inhibits 6HB formation by targeting NHR and lipids. Development of new fusion inhibitors, especially small molecule drugs, is encouraged to overcome the shortcomings of T20 as a peptide drug. Hydrophobic characteristics and membrane association are critical for gp41 function and mechanism of action. Research in gp41-membrane interactions, using peptides corresponding to specific functional domains, or constructs including several interactive domains, are reviewed here to get a better understanding of gp41 mediated virus-cell fusion that can inform or guide the design of new HIV-1 fusion inhibitors.
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Affiliation(s)
- Lifeng Cai
- Beijing Institute of Pharmacology & Toxicology, Haidian District, Beijing 100850, China.
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22
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Molecular dynamics simulation of HIV fusion inhibitor T-1249: insights on peptide-lipid interaction. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2012; 2012:151854. [PMID: 22675399 PMCID: PMC3364549 DOI: 10.1155/2012/151854] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 03/08/2012] [Accepted: 03/20/2012] [Indexed: 12/19/2022]
Abstract
T-1249 is a peptide that inhibits the fusion of HIV envelope with the target cell membrane. Recent results indicate that T-1249, as in the case of related inhibitor peptide T-20 (enfuvirtide), interacts with membranes, more extensively in the bilayer liquid disordered phase than in the liquid ordered state, which could be linked to its effectiveness. Extensive molecular dynamics simulations (100 ns) were carried out to investigate the interaction between T-1249 and bilayers of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) and POPC/cholesterol (1 : 1). It was observed that T-1249 interacts to different extents with both membrane systems and that peptide interaction with the bilayer surface has a local effect on membrane structure. Formation of hydrogen bonding between certain peptide residues and several acceptor and donor groups in the bilayer molecules was observed. T-1249 showed higher extent of interaction with bilayers when compared to T-20. This is most notable in POPC/Chol membranes, owing to more peptide residues acting as H bond donors and acceptors between the peptide and the bilayer lipids, including H-bonds formed with cholesterol. This behavior is at variance with that of T-20, which forms no H bonds with cholesterol. This higher ability to interact with membranes is probably correlated with its higher inhibitory efficiency.
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23
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Henriques ST, Craik DJ. Importance of the cell membrane on the mechanism of action of cyclotides. ACS Chem Biol 2012; 7:626-36. [PMID: 22260456 DOI: 10.1021/cb200395f] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Their distinctive structures, diverse range of bioactivities, and potential for pharmaceutical or agricultural applications make cyclotides an intriguing family of cyclic peptides. Together with the physiological role in plant host defense, cyclotides possess antimicrobial, anticancer, and anti-HIV activities. In all of the reported activities, cell membranes seem to be the primary target for cyclotide binding. This article examines recent literature on cyclotide-membrane studies and highlights the hypothesis that the activity of cyclotides is dependent on their affinity for lipid bilayers and enhanced by the presence of specific lipids, i.e., phospholipids containing phosphatidylethanolamine headgroups. There is growing evidence that the lipid composition of target cell membranes dictates the amount of cyclotides bound to the cell and the extent of their activity. After membrane targeting and insertion in the bilayer core, cyclotides induce disruption of membranes by a pore formation mechanism. This proposed mechanism of action is supported by biophysical studies with model membranes and by studies on natural biological membranes of known lipid compositions.
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Affiliation(s)
- Sónia Troeira Henriques
- Institute
for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- Institute of Molecular Medicine,
Medical School, University of Lisbon, 1649-028
Lisbon, Portugal
| | - David J. Craik
- Institute
for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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24
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Kapoor DN, Katare OP, Dhawan S. In situ forming implant for controlled delivery of an anti-HIV fusion inhibitor. Int J Pharm 2012; 426:132-143. [DOI: 10.1016/j.ijpharm.2012.01.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 01/06/2012] [Accepted: 01/06/2012] [Indexed: 11/30/2022]
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25
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Nomura W, Hashimoto C, Ohya A, Miyauchi K, Urano E, Tanaka T, Narumi T, Nakahara T, Komano JA, Yamamoto N, Tamamura H. A synthetic C34 trimer of HIV-1 gp41 shows significant increase in inhibition potency. ChemMedChem 2012; 7:205-8. [PMID: 22247043 DOI: 10.1002/cmdc.201100542] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 12/15/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Wataru Nomura
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
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26
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Gochin M, Zhou G. Amphipathic properties of HIV-1 gp41 fusion inhibitors. Curr Top Med Chem 2011; 11:3022-32. [PMID: 22044226 PMCID: PMC3219813 DOI: 10.2174/156802611798808488] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 02/26/2011] [Accepted: 12/01/2011] [Indexed: 12/11/2022]
Abstract
Small molecule inhibition of HIV fusion has been an elusive goal, despite years of effort by both pharmaceutical and academic laboratories. In this review, we will discuss the amphipathic properties of both peptide and small molecule inhibitors of gp41-mediated fusion. Many of the peptides and small molecules that have been developed target a large hydrophobic pocket situated within the grooves of the coiled coil, a potential hotspot for inhibiting the trimer of hairpin formation that accompanies fusion. Peptide studies reveal molecular properties required for effective inhibition, including elongated structure and lipophilic or amphiphilic nature. The characteristics of peptides that bind in this pocket provide features that should be considered in small molecule development. Additionally, a novel site for small molecule inhibition of fusion has recently been suggested, involving residues of the loop and fusion peptide. We will review the small molecule structures that have been developed, evidence pointing to their mechanism of action and strategies towards improving their affinity. The data points to the need for a strongly amphiphilic character of the inhibitors, possibly as a means to mediate the membrane - protein interaction that occurs in gp41 in addition to the protein - protein interaction that accompanies the fusion-activating conformational transition.
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Affiliation(s)
- Miriam Gochin
- Department of Basic Sciences, Touro University – California, Vallejo, CA 94592, USA.
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27
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do Canto AM, Carvalho AP, Ramalho JP, Loura LM. Molecular dynamics simulations of T-20 HIV fusion inhibitor interacting with model membranes. Biophys Chem 2011; 159:275-86. [DOI: 10.1016/j.bpc.2011.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/31/2011] [Accepted: 08/01/2011] [Indexed: 10/17/2022]
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28
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29
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Hashimoto C, Tanaka T, Narumi T, Nomura W, Tamamura H. The successes and failures of HIV drug discovery. Expert Opin Drug Discov 2011; 6:1067-90. [DOI: 10.1517/17460441.2011.611129] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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30
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Matos PM, Freitas T, Castanho MARB, Santos NC. The role of blood cell membrane lipids on the mode of action of HIV-1 fusion inhibitor sifuvirtide. Biochem Biophys Res Commun 2010; 403:270-4. [PMID: 21075080 DOI: 10.1016/j.bbrc.2010.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 11/03/2010] [Indexed: 11/29/2022]
Abstract
Sifuvirtide is a gp41 based peptide that inhibits HIV-1 fusion with the host cells and is currently under clinical trials. Previous studies showed that sifuvirtide partitions preferably to saturated phosphatidylcholine lipid membranes, instead of fluid-phase lipid vesicles. We extended the study to the interaction of the peptide with circulating blood cells, by using the dipole potential sensitive probe di-8-ANEPPS. Sifuvirtide decreased the dipole potential of erythrocyte and lymphocyte membranes in a concentration dependent manner, demonstrating its interaction. Also, the lipid selectivity of the peptide towards more rigid phosphatidylcholines was confirmed based on the dipole potential variations. Overall, the interaction of the peptide with the cell membranes is a contribution of different lipid preferences that presumably directs the peptide towards raft-like domains where the receptors are located, facilitating the reach of the peptide to its molecular target, the gp41 in its pre-fusion conformation.
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Affiliation(s)
- Pedro M Matos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisbon, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
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31
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Quantitative assessment of peptide–lipid interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1999-2012. [DOI: 10.1016/j.bbamem.2010.07.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 07/13/2010] [Accepted: 07/13/2010] [Indexed: 11/23/2022]
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32
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Franquelim HG, Veiga AS, Weissmüller G, Santos NC, Castanho MA. Unravelling the molecular basis of the selectivity of the HIV-1 fusion inhibitor sifuvirtide towards phosphatidylcholine-rich rigid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1234-43. [DOI: 10.1016/j.bbamem.2010.02.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 01/19/2010] [Accepted: 02/08/2010] [Indexed: 11/29/2022]
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33
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Martins do Canto A, Palace Carvalho A, Prates Ramalho J, Loura LM. Structure and conformation of HIV fusion inhibitor peptide T-1249 in presence of model membranes: A molecular dynamics study. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.theochem.2009.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Matos PM, Castanho MARB, Santos NC. HIV-1 fusion inhibitor peptides enfuvirtide and T-1249 interact with erythrocyte and lymphocyte membranes. PLoS One 2010; 5:e9830. [PMID: 20352107 PMCID: PMC2843717 DOI: 10.1371/journal.pone.0009830] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 03/02/2010] [Indexed: 11/18/2022] Open
Abstract
Enfuvirtide and T-1249 are two HIV-1 fusion inhibitor peptides that bind to gp41 and prevent its fusogenic conformation, inhibiting viral entry into host cells. Previous studies established the relative preferences of these peptides for membrane model systems of defined lipid compositions. We aimed to understand the interaction of these peptides with the membranes of erythrocytes and peripheral blood mononuclear cells. The peptide behavior toward cell membranes was followed by di-8-ANEPPS fluorescence, a lipophilic probe sensitive to the changes in membrane dipole potential. We observed a fusion inhibitor concentration-dependent decrease on the membrane dipole potential. Quantitative analysis showed that T-1249 has an approximately eight-fold higher affinity towards cells, when compared with enfuvirtide. We also compared the binding towards di-8-ANEPPS labeled lipid vesicles that model cell membranes and obtained concordant results. We demonstrated the distinct enfuvirtide and T-1249 membranotropism for circulating blood cells, which can be translated to a feasible in vivo scenario. The enhanced interaction of T-1249 with cell membranes correlates with its higher efficacy, as it can increase and accelerate the drug binding to gp41 in its pre-fusion state.
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Affiliation(s)
- Pedro M. Matos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Miguel A. R. B. Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
- * E-mail:
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35
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Jin H, Kagiampakis I, Li P, Liwang PJ. Structural and functional studies of the potent anti-HIV chemokine variant P2-RANTES. Proteins 2010; 78:295-308. [PMID: 19722264 DOI: 10.1002/prot.22542] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The N-terminal region of the chemokine RANTES is critical for its function. A synthesized N-terminally modified analog of RANTES, P2-RANTES, was discovered using a phage display selection against living CCR5-expressing cells, and has been reported to inhibit HIV-1 env-mediated cell-cell fusion at subnanomolar levels (Hartley et al. J Virol 2003;77:6637-6644). In the present study we produced this protein using E. coli overexpression and extensively studied its structure and function. The x-ray crystal structure of P2-RANTES was solved and refined at 1.7 A resolution. This protein was found to be predominantly a monomer in solution by analytical ultracentrifugation, but a tetramer in the crystal. In studies of glycosaminoglycan binding, P2-RANTES was found to be significantly less able to bind heparin than wild type RANTES. We also tested this protein for receptor internalization where it was shown to be functional, in cell-cell fusion assays where recombinant P2-RANTES was a potent fusion inhibitor (IC(50) = 2.4 +/- 0.8 nM), and in single round infection assays where P2-RANTES inhibited at subnanomolar levels. Further, in a modified fusion assay designed to test specificity of inhibition, P2-RANTES was also highly effective, with a 65-fold improvement over the fusion inhibitor C37, which is closely related to the clinically approved inhibitor T-20. These studies provide detailed structural and functional information for this novel N-terminally modified chemokine mutant. This information will be very useful in the development of more potent anti-HIV agents. PDB Accession Number: 2vxw.
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Affiliation(s)
- Hongjun Jin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, USA
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Membrane microheterogeneity: Förster resonance energy transfer characterization of lateral membrane domains. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:589-607. [DOI: 10.1007/s00249-009-0547-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 09/14/2009] [Accepted: 09/24/2009] [Indexed: 01/20/2023]
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37
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Pérez-Berná AJ, Pabst G, Laggner P, Villalaín J. Biophysical characterization of the fusogenic region of HCV envelope glycoprotein E1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2183-93. [PMID: 19698697 DOI: 10.1016/j.bbamem.2009.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/27/2009] [Accepted: 08/04/2009] [Indexed: 01/08/2023]
Abstract
We have studied the binding and interaction of the peptide E1(FP) with various model membranes. E1(FP) is derived from the amino acid segment 274-291 of the hepatitis C virus envelope glycoprotein E1, which was previously proposed to host the peptide responsible for fusion to target membranes. In the present study we addressed the changes which take place upon E1(FP) binding in both the peptide and the phospholipid bilayer, respectively, through a series of complementary experiments. We show that peptide E1(FP) binds to and interacts with phospholipid model membranes, modulates the polymorphic phase behavior of membrane phospholipids, is localized in a shallow position in the membrane and interacts preferentially with cholesterol. The capability of modifying the biophysical properties of model membranes supports its role in HCV-mediated membrane fusion and suggests that the mechanism of membrane fusion elicited by class I and II fusion proteins might be similar.
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Affiliation(s)
- Ana J Pérez-Berná
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, E-03202 Alicante, Spain
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Henriques ST, Pattenden LK, Aguilar MI, Castanho MARB. The Toxicity of Prion Protein Fragment PrP(106−126) is Not Mediated by Membrane Permeabilization as Shown by a M112W Substitution. Biochemistry 2009; 48:4198-208. [DOI: 10.1021/bi900009d] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sónia Troeira Henriques
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Egas Moniz, Edifício Egas Moniz, 1649-028 Lisboa, Portugal
| | - Leonard Keith Pattenden
- Department of Biochemistry & Molecular Biology, Monash University, Victoria, 3800 Clayton, Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry & Molecular Biology, Monash University, Victoria, 3800 Clayton, Australia
| | - Miguel A. R. B. Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Egas Moniz, Edifício Egas Moniz, 1649-028 Lisboa, Portugal
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Addition of a cholesterol group to an HIV-1 peptide fusion inhibitor dramatically increases its antiviral potency. Proc Natl Acad Sci U S A 2009; 106:5801-6. [PMID: 19297617 DOI: 10.1073/pnas.0901007106] [Citation(s) in RCA: 173] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Peptides derived from the heptad repeat 2 (HR2) region of the HIV fusogenic protein gp41 are potent inhibitors of viral infection, and one of them, enfuvirtide, is used for the treatment of therapy-experienced AIDS patients. The mechanism of action of these peptides is binding to a critical intermediate along the virus-cell fusion pathway, and accordingly, increasing the affinity for the intermediate yields more potent inhibitors. We took a different approach, namely to increase the potency of the HR2 peptide inhibitor C34 by targeting it to the cell compartment where fusion occurs, and we show here that a simple, yet powerful way to accomplish this is attachment of a cholesterol group. C34 derivatized with cholesterol (C34-Chol) shows dramatically increased antiviral potency on a panel of primary isolates, with IC(90) values 15- to 300-fold lower than enfuvirtide and the second-generation inhibitor T1249, making C34-Chol the most potent HIV fusion inhibitor to date. Consistent with its anticipated mechanism of action, the antiviral activity of C34-Chol is unusually persistent: washing target cells after incubation with C34-Chol, but before triggering fusion, increases IC(50) only 7-fold, relative to a 400-fold increase observed for C34. Moreover, derivatization with cholesterol extends the half-life of the peptide in vivo. In the mouse, s.c. administration of 3.5 mg/kg C34-Chol yields a plasma concentration 24 h after injection >300-fold higher than the measured IC(90) values. Because the fusion machinery targeted by C34-Chol is similar in several other enveloped viruses, we believe that these findings may be of general utility.
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Manikandan S, Malik BK. Modeling of human CCR5 as target for HIV-I and virtual screening with marine therapeutic compounds. Bioinformation 2008; 3:89-94. [PMID: 19238197 PMCID: PMC2639675 DOI: 10.6026/97320630003089] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 09/21/2008] [Indexed: 12/02/2022] Open
Abstract
Marine derivatives are of great pharmaceutical interest as inhibitory compound and search of bioactive compounds from Marine
organism which is relatively new to medicinal chemistry. Our main aim in the study is to screen possible inhibitors against
CCR5 which acts as co-receptor M-tropic HIV-1, through virtual screening of 122 Marine derived compounds from various
organisms known to have biological activity. Homology Model of CCR5 was constructed using MODELLER and the Model was energy
minimized and validated using PROCHECK to obtain a stable structure, which was further used for virtual screening of Marine
derived compounds through molecular Docking studies using GOLD. The Docked complexes were validated and Enumerated based on
the GOLD Scoring function to pick out the best Marine inhibitor based on GOLD score. Thus from the entire 122 Marine
compounds which were Docked, we got best 4 of them with optimal GOLD Score.
(LAMIVUDINE: 45.0218, BATZELLINE-D: 44.3852.ACYCLOVIR: 43.1362 and THIIOACETAMIDE: 42.7412) Further the Complexes were analyzed
through LIGPLOT for their interaction for the 4 best docked Marine compounds. Thus from the Complex scoring and binding ability its
deciphered that these Marine compounds could be promising inhibitors for M-tropic HIV-1 using CCR5 as Drug target yet pharmacological
studies have to confirm it.
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41
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Vieira CR, Castanho M, Saldanha C, Santos NC. Enfuvirtide effects on human erythrocytes and lymphocytes functional properties. J Pept Sci 2008; 14:448-54. [PMID: 18196497 DOI: 10.1002/psc.1006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Enfuvirtide (T-20) is the first inhibitor of human Immunodeficiency Virus type-1 (HIV-1) entrance on a target cell approved for clinical use. Recent studies indicated that its action mechanism involves the interaction with the membrane surface, increasing the concentration in the site of action. In the present study, the in vitro interaction between enfuvirtide and blood cells of healthy human donors, namely erythrocytes and lymphocytes, and the peptide effect on plasma and lymphocyte suspensions supernatant ions were evaluated, in order to better characterize the action of this peptide. Enfuvirtide causes a decrease in the concentration of hemoglobin and in the percentages of methemoglobin and carboxyhemoglobin, together with increased values of P50, pCO2, and [HCO3-], and significant decreases of pO2 and pH, in blood plasma. The supernatants of lymphocyte suspensions derived from blood incubated with enfuvirtide presented a decrease in pH and [HCO3-]. Fluorescence anisotropy measurements of 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4-(trimethylamino)-phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), used to assess erythrocyte and lymphocyte membrane fluidity, did not yield enfuvirtide-induced changes (an effect could be expected due to peptide partition to lipid bilayers). Erythrocytes incubated with high enfuvirtide concentrations showed a significant decrease in osmotic fragility. As for erythrocyte deformability, enfuvirtide leads to increased elongation indexes for low shear stress values, whereas for high shear stress values it has the opposite effect. Despite the observed statistically significant variations in several parameters, these enfuvirtide-induced changes are not expected to lead to any detectable biomedical outcome for enfuvirtide-treated patients.
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Affiliation(s)
- Catarina R Vieira
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
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42
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Franquelim HG, Loura LMS, Santos NC, Castanho MARB. Sifuvirtide screens rigid membrane surfaces. establishment of a correlation between efficacy and membrane domain selectivity among HIV fusion inhibitor peptides. J Am Chem Soc 2008; 130:6215-23. [PMID: 18410103 DOI: 10.1021/ja711247n] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Sifuvirtide, a 36 amino acid negatively charged peptide, is a novel and promising HIV fusion inhibitor, presently in clinical trials. Because of the aromatic amino acid residues of the peptide, its behavior in aqueous solution and the interaction with lipid-membrane model systems (large unilammelar vesicles) were studied by using mainly fluorescence spectroscopy techniques (both steady-state and time-resolved). No significant aggregation of the peptide was observed with aqueous solution. Various biological and nonbiological lipid-membrane compositions were analyzed, and atomic force microscopy was used to visualize phase separation in several of those mixtures. Results showed no significant interaction of the peptide, neither with zwitterionic fluid lipid membranes (liquid-disordered phase), nor with cholesterol-rich membranes (liquid-ordered phase). However, significant partitioning was observed with the positively charged lipid models (K(p) = (2.2 +/- 0.3) x 10(3)), serving as a positive control. Fluorescence quenching using Förster resonance acrylamide and lipophilic probes was carried out to study the location of the peptide in the membrane models. In the gel-phase DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) membrane model, an adsorption of the peptide at the surface of these membranes was observed and confirmed by using Förster resonance energy-transfer experiments. These results indicate a targeting of the peptide to gel-phase domains relatively to liquid-disordered or liquid-ordered phase domains. This larger affinity and selectivity toward the more rigid areas of the membranes, where most of the receptors are found, or to viral membrane, may help explain the improved clinical efficiency of sifuvirtide, by providing a local increased concentration of the peptide at the fusion site.
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Affiliation(s)
- Henri G Franquelim
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
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43
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Martins Do Canto AMT, Palace Carvalho AJ, Prates Ramalho JP, Loura LMS. T-20 and T-1249 HIV fusion inhibitors' structure and conformation in solution: a molecular dynamics study. J Pept Sci 2008; 14:442-7. [DOI: 10.1002/psc.982] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Bharatham K, Bharatham N, Park KH, Lee KW. Binding mode analyses and pharmacophore model development for sulfonamide chalcone derivatives, a new class of alpha-glucosidase inhibitors. J Mol Graph Model 2007; 26:1202-12. [PMID: 18096420 DOI: 10.1016/j.jmgm.2007.11.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 11/07/2007] [Accepted: 11/07/2007] [Indexed: 11/29/2022]
Abstract
Sulfonamide chalcone derivatives are a new class of non-saccharide compounds that effectively inhibit glucosidases which are the major targets in the treatment of Type 2 diabetes and HIV infection. Our aim is to explore their binding mode of interaction at the active site by comparing with the sugar derivatives and to develop a pharmacophore model which would represent the critical features responsible for alpha-glucosidase inhibitory activity. The homology modeled structure of Saccharomyces cerevisiae alpha-glucosidase was built and used for molecular docking of non-sugar/sugar derivatives. The validated docking results projected the crucial role of NH group in the binding of sugar/non-sugar derivatives to the active site. Ligplot analyses revealed that Tyr71, and Phe177 form hydrophobic interactions with sugar/non-sugar derivatives by holding the terminal glycosidic ring mimics. Molecular dynamic (MD) simulation studies were performed for protein alone and with chalcone derivative to prove its binding mechanism as shown by docking/Ligplot results. It would also help to substantiate the homology modeled structure stability. With the knowledge of the crucial interactions between ligand and protein from docking and MD simulation studies, features for pharmacophore model development were chosen. The CATALYST/HipHop was used to generate a five featured pharmacophore model with a training set of five non-sugar derivatives. As validation, all the crucial features of the model were perfectly mapped onto the 3D structures of the sugar derivatives as well as the newly tested non-sugar derivatives. Thus, it can be useful in virtual screening for finding new non-sugar derivatives as alpha-glucosidase inhibitors.
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Affiliation(s)
- Kavitha Bharatham
- Division of Applied Life Science (BK21 Program), Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea
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45
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Liu S, Jing W, Cheung B, Lu H, Sun J, Yan X, Niu J, Farmar J, Wu S, Jiang S. HIV gp41 C-terminal heptad repeat contains multifunctional domains. Relation to mechanisms of action of anti-HIV peptides. J Biol Chem 2007; 282:9612-9620. [PMID: 17276993 DOI: 10.1074/jbc.m609148200] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
T20 (Fuzeon), a novel anti-human immunodeficiency virus (HIV) drug, is a peptide derived from HIV-1 gp41 C-terminal heptad repeat (CHR). Its mechanism of action has not yet been defined. We applied Pepscan strategy to determine the relationship between functional domains and mechanisms of action of five 36-mer overlapping peptides with a shift of five amino acids (aa): CHR-1 (aa 623-658), C36 (aa 628-663), CHR-3 (aa 633-668), T20 (aa 638-673), and CHR-5 (aa 643-678). C36 is a peptide with addition of two aa to the N terminus of C34. Peptides CHR-1 and C36 contain N-terminal heptad repeat (NHR)- and pocket-binding domains. They inhibited HIV-1 fusion by interacting with gp41 NHR, forming stable six-helix bundles and blocking gp41 core formation. Peptide T20 containing partial NHR- and lipid-binding domains, but lacking pocket-binding domain, blocked viral fusion by binding its N- and C-terminal sequences with gp41 NHR and cell membrane, respectively. Peptide CHR-3, which is located in the middle between C36 and T20, overlaps >86% of the sequences of these two peptides, and lacks pocket- and lipid-binding domains, exhibited marginal anti-HIV-1 activity. These results suggest that T20 and C36 contain different functional domains, through which they inhibit HIV-1 entry with distinct mechanisms of action. The multiple functional domains in gp41 CHR and their binding partners may serve as targets for rational design of new anti-HIV-1 drugs and vaccines.
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Affiliation(s)
- Shuwen Liu
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
| | - Weiguo Jing
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - Byron Cheung
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - Hong Lu
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - Jane Sun
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - Xuxia Yan
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - Jinkui Niu
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - James Farmar
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021
| | - Shuguang Wu
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Shibo Jiang
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China; Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021.
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46
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Martins-Silva J, Santos NC, Doroana M, Duarte N, Tavares L, Antunes F, Saldanha C. Changes in blood cell membrane properties in HIV type-1-infected patients. AIDS Res Hum Retroviruses 2006; 22:849-53. [PMID: 16989609 DOI: 10.1089/aid.2006.22.849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To evaluate the possible HIV-1 infection-induced changes in cell membrane properties and in calcium signaling, membrane fluidity, acetylcholinesterase (AChE, a glycosylphosphatidylinositol-anchored protein) activity, and intracellular calcium concentration ([Ca2(+)](int)) were evaluated in lymphocytes and erythrocytes of infected individuals, previous to their engagement in antiretroviral therapy. Membrane fluidity was assessed by fluorescence spectroscopy measurements, using the fluorescence probes 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-[4-(trimethylamino)-phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). AChE activity was determined by the colorimetric Ellman's method and [Ca2(+)](int) using the fluorescent fura-2 acetoxymethyl ester. When compared with the control group, lymphocytes of infected patients presented significantly decreased membrane fluidity, decreased AChE activity, and increased [Ca2(+)](int). Erythrocytes from HIV-infected patients presented decreased [Ca2(+)](int) when compared with the control group and decreased membrane fluidity near the lipid/water interface. Our data show that HIV-1 infection leads to biochemical and biophysical changes in the membrane itself and in membrane protein activity in lymphocytes (average of infected and noninfected subpopulations) and even in erythrocytes. The present observations are in agreement with a process of facilitated propagation of the infection to new cells, stimulation of virion production, and maintenance of a reservoir of erythrocyte-bound infectious virus.
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Affiliation(s)
- J Martins-Silva
- Instituto de Biopatologia Química/Faculdade de Medicina de Lisboa and Unidade de Biopatologia Vascular/Instituto de Medicina Molecular, 1649-028 Lisboa, Portugal
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47
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Lopes SCDN, Fedorov A, Castanho MARB. Chiral Recognition ofD-Kyotorphin by Lipidic Membranes: Relevance Toward Improved Analgesic Efficiency. ChemMedChem 2006; 1:723-8. [PMID: 16902926 DOI: 10.1002/cmdc.200600096] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
D-Kyotorphin (D-KTP), the most potent isomer of the endorphin-like dipeptide kyotorphin (KTP), is a good drug candidate for the treatment of chronic pain and is thought to be involved in receptor-mediated processes. According to the "membrane catalysis" model, ligands interact with membrane lipids to attain high local concentrations in the receptor vicinity and to adopt the necessary conformation for docking. Therefore, the interaction and recognition of D-KTP by membranes is potentially important to its increased analgesic effect. In spite of the neutral net charge of D-KTP at pH 7.4, fluorescence spectroscopy reveals that the interaction with large unilamellar vesicles is more extensive than was observed for KTP. The tyrosine residue interacts extensively with rigid membranes, with a location and well-defined orientation in the bilayer. This suggests not only that D-KTP meets the structural constraints needed for receptor-ligand interaction in a manner similar to that of KTP, but also that the stronger membrane interaction and ability to discriminate rigid membrane domains might contribute to its improved analgesic effect.
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Affiliation(s)
- Sílvia C D N Lopes
- Centro de Química-Física Molecular, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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48
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Cohen L, Gilles N, Karbat I, Ilan N, Gordon D, Gurevitz M. Direct evidence that receptor site-4 of sodium channel gating modifiers is not dipped in the phospholipid bilayer of neuronal membranes. J Biol Chem 2006; 281:20673-20679. [PMID: 16720570 DOI: 10.1074/jbc.m603212200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In a recent note to Nature, R. MacKinnon has raised the possibility that potassium channel gating modifiers are able to partition in the phospholipid bilayer of neuronal membranes and that by increasing their partial concentration adjacent to their receptor, they affect channel function with apparent high affinity (Lee and MacKinnon (2004) Nature 430, 232-235). This suggestion was adopted by Smith et al. (Smith, J. J., Alphy, S., Seibert, A. L., and Blumenthal, K. M. (2005) J. Biol. Chem. 280, 11127-11133), who analyzed the partitioning of sodium channel modifiers in liposomes. They found that certain modifiers were able to partition in these artificial membranes, and on this basis, they have extrapolated that scorpion beta-toxins interact with their channel receptor in a similar mechanism as that proposed by MacKinnon. Since this hypothesis has actually raised a new conception, we examined it in binding assays using a number of pharmacologically distinct scorpion beta-toxins and insect and mammalian neuronal membrane preparations, as well as by analyzing the rate by which the toxin effect on gating of Drosophila DmNa(v)1 and rat brain rNa(v)1.2a develops. We show that in general, scorpion beta-toxins do not partition in neuronal membranes and that in the case in which a depressant beta-toxin partitions in insect neuronal membranes, this partitioning is unrelated to its interaction with the receptor site and the effect on the gating properties of the sodium channel. These results negate the hypothesis that the high affinity of beta-toxins for sodium channels is gained by their ability to partition in the phospholipid bilayer and clearly indicate that the receptor site for scorpion beta-toxins is accessible to the extracellular solvent.
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Affiliation(s)
- Lior Cohen
- Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv 69978, Tel-Aviv, Israel
| | - Nicolas Gilles
- Commissariat à l'Energie Atomique, Department d'Ingenierie et d'Etudes des Proteines, C.E. Saclay, F-91191 Gif Sur Yvette Cedex, France
| | - Izhar Karbat
- Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv 69978, Tel-Aviv, Israel
| | - Nitza Ilan
- Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv 69978, Tel-Aviv, Israel
| | - Dalia Gordon
- Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv 69978, Tel-Aviv, Israel.
| | - Michael Gurevitz
- Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv 69978, Tel-Aviv, Israel.
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49
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Veiga AS, Castanho MARB. The membranes' role in the HIV-1 neutralizing monoclonal antibody 2F5 mode of action needs re-evaluation. Antiviral Res 2006; 71:69-72. [PMID: 16530275 DOI: 10.1016/j.antiviral.2006.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 01/05/2006] [Accepted: 02/03/2006] [Indexed: 11/21/2022]
Abstract
2F5, a monoclonal antibody that neutralizes HIV-1 primary isolates, recognizes an epitope in the membrane proximal region of the glycoprotein gp41 ectodomain. It is believed that binding to the viral membrane is a step in the antibody mode of action, as usual in ligand membrane receptor interactions. We investigated the interaction of 2F5 with membrane model systems, namely large unilamellar vesicles, by means of fluorescence techniques. There were no significant interactions of 2F5 with model viral membranes or with model target cell membranes. Thus, the usual three-step 'membrane catalysis' method is not followed by 2F5 in its mode of action.
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Affiliation(s)
- Ana Salomé Veiga
- Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Campo Grande Ed. C8, Portugal
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50
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From Lipid Phases to Membrane Protein Organization: Fluorescence Methodologies in the Study of Lipid-Protein Interactions. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/3-540-28435-4_1] [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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