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Vieira FM, Pereira FB, Ribeiro LB, Oliveira JB, Silva DCN, Muniz-Pereira LC, Felix-Nascimento G. Oswaldocruzia franciscoensis n. sp. (Nematoda: Molineidae) in Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae) from Caatinga morphoclimatic domain, Brazil: morphological and molecular characterisation. J Helminthol 2023; 97:e104. [PMID: 38148677 DOI: 10.1017/s0022149x23000858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
A new species of Oswaldocruzia Travassos, 1917 (Nematoda, Molineidae), parasite of Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae), from Caatinga morphoclimatic domain, Brazil, is described based on morphological and molecular data. Oswaldocruzia franciscoensis n. sp. is characterised by an anterior extremity with a cephalic vesicle divided into two portions, a body covered by cuticular longitudinal ridges, and cervical alae. Males of the new species have caudal bursa of type I with a 2-1-2 pattern, spicules divided into a shoe, bifurcated fork, and blade with two unequal branches, in which the longer branch bifurcates at its distal portion end and the smaller branch with three distal processes, each with distal bifurcations. Females have didelphic and amphidelphic uteri, an ovijector divided into vestibule, anterior and posterior sphincters, and anterior and posterior infundibula. The new species differs from its Neotropical congeners that have caudal bursa of type I, based on the presence of cervical alae and by having a spicular blade distally divided into two unequal branches, with the longer branch bifurcating at its distal portion and smaller branch with three distal processes, each distally bifurcated. The partial 18S rDNA sequence generated for Oswaldocruzia franciscoensis n. sp. is the first of a representative belonging to this genus in the Neotropical region.
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Affiliation(s)
- F M Vieira
- Campus de Ciências Agrárias, Universidade Federal do Vale do São Francisco (UNIVASF), Rodovia BR-407, KM 12 Lote 543 S/n Projeto de Irrigação Nilo Coelho, Petrolina, 56300-000, Brazil
| | - F B Pereira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Bloco L4 sala 252, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG31270-901, Brazil
| | - L B Ribeiro
- Campus de Ciências Agrárias, Universidade Federal do Vale do São Francisco (UNIVASF), Rodovia BR-407, KM 12 Lote 543 S/n Projeto de Irrigação Nilo Coelho, Petrolina, 56300-000, Brazil
| | - J B Oliveira
- Laboratório de Parasitologia, Universidade Federal Rural de Pernambuco (UFRPE), Rua Dom Manoel de Medeiros s/nº, Recife CEP 52051-360, Brazil
| | - D C N Silva
- Campus de Ciências Agrárias, Universidade Federal do Vale do São Francisco (UNIVASF), Rodovia BR-407, KM 12 Lote 543 S/n Projeto de Irrigação Nilo Coelho, Petrolina, 56300-000, Brazil
| | - L C Muniz-Pereira
- Laboratório de Helmintos Parasitos de Vertebrados, Instituto Oswaldo Cruz, FIOCRUZ. Av. Brasil 4365, Rio de Janeiro CEP 21040-900, Brazil
| | - G Felix-Nascimento
- Campus de Ciências Agrárias, Universidade Federal do Vale do São Francisco (UNIVASF), Rodovia BR-407, KM 12 Lote 543 S/n Projeto de Irrigação Nilo Coelho, Petrolina, 56300-000, Brazil
- Laboratório de Anatomia dos Animais Domésticos e Silvestres (LAADS), Universidade Federal do Vale do São Francisco (UNIVASF), Rodovia BR-407, Km. 12 Lote 543 s/n Projeto de Irrigação Nilo Coelho, Petrolina, Pernambuco56300-000, Brazil
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Frizzo A, Aguiari AG, Andrade SS, Pereira FB, Benites BD, Alves SCR. VALIDATION OF LONGER FRESH STORAGE TIME FOR PERIPHERAL BLOOD STEM CELLS INTENDED FOR CLINICAL USE. Hematol Transfus Cell Ther 2022. [DOI: 10.1016/j.htct.2022.09.510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Pereira FB, Oliveira CBS, Marques JVG, Langkamer MFB, Ferreira MIM, Fusrtenau SC, Carvalho LRDMS, Melo GFD, Ferrari EP. Sports participation among Brazilian adolescents and children: systematic review. Rev bras cineantropom desempenho hum 2022. [DOI: 10.1590/1980-0037.2022v24e86739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abstract The aim of this study is to describe the prevalence of sports participation in Brazilian children and adolescents through a systematic literature review. A search was carried out in the following electronic databases: MEDLINE, WEB OF SCIENCE, BIREME, SCIELO, and SCOPUS for manuscripts published until 2020, combining the keywords: “children”, “adolescents”, “prevalence”, and “sports participation”, in Portuguese and English. Twenty-six articles published between 2003 and 2020 were included in the review, with the aim of estimating the prevalence of participation in organized sports in Brazilian children and adolescents. Considering the regions where the studies were carried out, the majority were developed in the south (57.7%; n=15), followed by the southeast (19.2%; n=05), and northeast (15.4%; n=04), in addition to 7.7% (n=02) in all regions of the country. The data showed prevalence of sports participation ranging from 15.0% to 73.2% (mean of 44.8%) among children and adolescents, being higher in males (63.1%). From the results found, the need to develop public policies is evident, in order to favor adherence and maintenance of young people to sports practice, especially among those of the female sex.
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Jesus WS, Prudente FV, Marques JMC, Pereira FB. Modeling microsolvation clusters with electronic-structure calculations guided by analytical potentials and predictive machine learning techniques. Phys Chem Chem Phys 2021; 23:1738-1749. [PMID: 33427847 DOI: 10.1039/d0cp05200k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We propose a new methodology to study, at the density functional theory (DFT) level, the clusters resulting from the microsolvation of alkali-metal ions with rare-gas atoms. The workflow begins with a global optimization search to generate a pool of low-energy minimum structures for different cluster sizes. This is achieved by employing an analytical potential energy surface (PES) and an evolutionary algorithm (EA). The next main stage of the methodology is devoted to establish an adequate DFT approach to treat the microsolvation system, through a systematic benchmark study involving several combinations of functionals and basis sets, in order to characterize the global minimum structures of the smaller clusters. In the next stage, we apply machine learning (ML) classification algorithms to predict how the low-energy minima of the analytical PES map to the DFT ones. An early and accurate detection of likely DFT local minima is extremely important to guide the choice of the most promising low-energy minima of large clusters to be re-optimized at the DFT level of theory. In this work, the methodology was applied to the Li+Krn (n = 2-14 and 16) microsolvation clusters for which the most competitive DFT approach was found to be the B3LYP-D3/aug-pcseg-1. Additionally, the ML classifier was able to accurately predict most of the solutions to be re-optimized at the DFT level of theory, thereby greatly enhancing the efficiency of the process and allowing its applicability to larger clusters.
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Affiliation(s)
- W S Jesus
- Instituto de Física, Universidade Federal da Bahia, 40170-115 Salvador, BA, Brazil.
| | - F V Prudente
- Instituto de Física, Universidade Federal da Bahia, 40170-115 Salvador, BA, Brazil.
| | - J M C Marques
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
| | - F B Pereira
- Coimbra Polytechnic - ISEC, Coimbra, Portugal and Centro de Informática e Sistemas da Universidade de Coimbra (CISUC), Coimbra, Portugal.
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Maya ÁTD, Assunção MJ, Brito CJ, Vieira E, Rosa TS, Pereira FB, de Toledo Nóbrega O, de França NM, Ferreira AP. High-intensity interval aerobic exercise induced a longer hypotensive effect when compared to continuous moderate. Sport Sci Health 2018. [DOI: 10.1007/s11332-018-0444-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Marques JMC, Pereira FB, Llanio-Trujillo JL, Abreu PE, Albertí M, Aguilar A, Pirani F, Bartolomei M. A global optimization perspective on molecular clusters. Philos Trans A Math Phys Eng Sci 2017; 375:rsta.2016.0198. [PMID: 28320902 PMCID: PMC5360898 DOI: 10.1098/rsta.2016.0198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/12/2016] [Indexed: 06/06/2023]
Abstract
Although there is a long history behind the idea of chemical structure, this is a key concept that continues to challenge chemists. Chemical structure is fundamental to understanding most of the properties of matter and its knowledge for complex systems requires the use of state-of-the-art techniques, either experimental or theoretical. From the theoretical view point, one needs to establish the interaction potential among the atoms or molecules of the system, which contains all the information regarding the energy landscape, and employ optimization algorithms to discover the relevant stationary points. In particular, global optimization methods are of major importance to search for the low-energy structures of molecular aggregates. We review the application of global optimization techniques to several molecular clusters; some new results are also reported. Emphasis is given to evolutionary algorithms and their application in the study of the microsolvation of alkali-metal and Ca2+ ions with various types of solvents.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.
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Affiliation(s)
- J M C Marques
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - F B Pereira
- Instituto Superior de Engenharia de Coimbra, Quinta da Nora, 3030-199 Coimbra, Portugal
- Centro de Informática e Sistemas da Universidade de Coimbra (CISUC), 3030-290 Coimbra, Portugal
| | - J L Llanio-Trujillo
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - P E Abreu
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - M Albertí
- IQTCUB, Departament de Ciència de Materials i Química Física, Universitat de Barcelona, 08028 Barcelona, Spain
| | - A Aguilar
- IQTCUB, Departament de Ciència de Materials i Química Física, Universitat de Barcelona, 08028 Barcelona, Spain
| | - F Pirani
- Dipartimento di Chimica, Biologia e Biotecnologie, Univertità di Perugia, 06123 Perugia, Italy
| | - M Bartolomei
- Consejo Superior de Investigaciones Científicas (IFF-CSIC), Instituto de Física Fundamental, Serrano 123, Madrid 28006, Spain
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Pereira FB, Leite AF, de Paula AP. Relationship between pre-sarcopenia, sarcopenia and bone mineral density in elderly men. Arch Endocrinol Metab 2015; 59:59-65. [PMID: 25926116 DOI: 10.1590/2359-3997000000011] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 10/10/2014] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Analyze the influence of sarcopenia in bone health of elderly men. SUBJECTS AND METHODS This cross-sectional study evaluated 198 men aged over 60 years. Body composition was measured by dual energy X-ray absorptiometry. The BMD was measured at the femoral neck, total hip, lumbar spine and 33% radius. The diagnosis of abnormal BMD was defined for men who presented densitometric diagnosis of osteopenia or osteoporosis defined by T-score of femoral neck, total hip and lumbar spine. The pre-sarcopenia and sarcopenia were defined according to the European Working Group on Sarcopenia in Older People. RESULTS The group diagnosed with normal BMD, compared to the group of abnormal BMD, have significantly higher body weight, body mass index, grip strength, lean mass, fat mass, and relative appendicular skeletal muscle mass (RASM). However, after multiple linear regression analysis, we found that only the RASM, lean mass, and handgrip strength in the dominant hand influenced the variability of the BMD after adjustment for age and weight. Regression analyzes showed a positive association between greater appendicular lean mass and a smaller number of elderly patients with abnormal BMD diagnostic. The regression analyzes showed that elderly men diagnosed with pre-sarcopenia and sarcopenia had more abnormal BMD than non-sarcopenic elderly men. CONCLUSION We concluded that pre-sarcopenia and sarcopenia were associated with abnormal BMD. The lean mass, compared to fat mass, has a greater positive influence on the BMD of elderly men. This result suggests the importance of the increase in lean mass for the bone health of elderly men.
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Sindeaux R, Figueiredo PTDS, de Melo NS, Guimarães ATB, Lazarte L, Pereira FB, de Paula AP, Leite AF. Fractal dimension and mandibular cortical width in normal and osteoporotic men and women. Maturitas 2013; 77:142-8. [PMID: 24289895 DOI: 10.1016/j.maturitas.2013.10.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 09/20/2013] [Accepted: 10/16/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To verify whether fractal dimensions (FD) on the mandibular trabecular and cortical bone and mandibular cortical width (MCW) differ between patients with normal bone mineral density (BMD) and osteoporosis. STUDY DESIGN In this retrospective study, 133 dental panoramic radiographs from men aged >60 years and postmenopausal women with a bone densitometry report of the lumbar spine and hip classified as either normal or osteoporotic were selected. Fractal dimensions of five standardized trabecular and cortical mandibular regions of interest and mandibular cortical width were measured on the panoramic radiographs by an experienced oral radiologist, blinded to the densitometric diagnosis. The following statistical analyses were performed: ANOVA and a forward logistic stepwise regression to verify associations between dental panoramic measurements and the densitometric diagnosis. P values less than .05 indicated statistical significance. MAIN OUTCOME MEASURES Fractal dimension and mandibular cortical width. RESULTS Differences were found in the FD values on mandibular cortical bone and MCW between patients with normal BMD and with osteoporosis, but not in the FD values of trabecular bone. The odds of having lower mean values of MCW and FD on cortical bone were 2.16, 3125 and 1005 times in osteoporotic patients, respectively, compared with patients with normal BMD. CONCLUSION The values of FD analysis on mandibular cortical bone and MCW were lower in women with osteoporosis. A well-adjusted logistic regression model showed that cortical bone measurements might be considered as auxiliary tools to referring patients for DXA exam.
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Affiliation(s)
| | | | - Nilce Santos de Melo
- Oral Pathology, Department of Dentistry, Faculty of Health Science, University of Brasília, Brazil
| | | | | | | | | | - André Ferreira Leite
- Oral Radiology, Department of Dentistry, Faculty of Health Science, University of Brasília, Brazil.
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Barra FR, Leite AF, Souza PTD, Pereira FB, Paula APD. [Quantitative ultrasound of the calcaneus, bone densitometry and vertebral morphometry in men over the age of 60 years]. Arq Bras Endocrinol Metabol 2012; 56:370-5. [PMID: 22990641 DOI: 10.1590/s0004-27302012000600005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 07/27/2012] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To compare calcaneal ultrasonometry and bone densitometry in the evaluation of morphometric vertebral fractures in men over 60 years of age. SUBJECTS AND METHODS We studied 96 men over 60 years of age by means of bone densitometry of the spine, femur and radius, lateral radiograph of the thoracic and lumbar spine, and calcaneal ultrasonometry. RESULTS Fifty-one percent of men had osteoporosis and vertebral fractures. Correlation was found between ultrasonometry stiffness index, T-score and bone mineral density of the spine, femur and radius (p < 0.01). Regarding the presence of fractures, there was a correlation only with BMD of the ultradistal radius (UD) and radius 33%. ROC curve showed accuracy only of UD radius BMD in detecting vertebral fractures. CONCLUSIONS Our study showed a correlation between osteoporosis diagnosis by ultrasonometry and densitometry in men over 60 years. It also showed a correlation between morphometric vertebral fracture and bone mineral density of the forearm.
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Pereira FB, Valpuesta JM, Basañez G, Goñi FM, Nieva JL. Interbilayer lipid mixing induced by the human immunodeficiency virus type-1 fusion peptide on large unilamellar vesicles: the nature of the nonlamellar intermediates. Chem Phys Lipids 1999; 103:11-20. [PMID: 10701076 DOI: 10.1016/s0009-3084(99)00087-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A peptide corresponding to the 23 N-terminal amino acid residues of the human immunodeficiency virus type-1 (HIV-1) gp41 has the capacity to induce intervesicular lipid mixing in large unilamellar liposomes composed of dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylethanolamine (DOPE) and cholesterol (CHOL) (molar ratio, 1:1:1). Cryo-transmission electron microscopy (cryo-TEM) of diluted vesicles to which peptides has been externally added reveals a morphology that is compatible with the formation of nonlamellar lipidic aggregates during the time-course of lipid mixing. 31P-nuclear magnetic resonance and 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMADPH) steady-state anisotropy data at equilibrium indicate that the peptide is able to modulate the lipid polymorphism in pelletted membranes by: (i) promoting the thermotropic formation of inverted phases; and (ii) driving the lamellar-to-nonlamellar transition towards the formation of isotropic phases. Therefore, our combined morphological and spectroscopic data reveal the existence of a direct correlation between the ability of the externally added peptide to induce lipid-mixing in dilute liposome samples and its capacity to modulate lipid polymorphism in stacked bilayers.
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Affiliation(s)
- F B Pereira
- Unidad de Biofísica (CSIC-EHU/UPV), Universidad del País Vasco, Bilbao, Spain
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Abstract
The membrane-interacting abilities of three sequences representing the putative fusogenic subdomain of the Ebola virus transmembrane protein have been investigated. In the presence of calcium, the sequence EBO(GE) (GAAIGLAWIPYFGPAAE) efficiently fused unilamellar vesicles composed of phosphatidylcholine, phosphatidylethanolamine, cholesterol, and phosphatidylinositol (molar ratio, 2:1:1:0.5), a mixture that roughly resembles the lipid composition of the hepatocyte plasma membrane. Analysis of the lipid dependence of the process demonstrated that the fusion activity of EBO(GE) was promoted by phosphatidylinositol but not by other acidic phospholipids. In comparison, EBO(EA) (EGAAIGLAWIPYFGPAA) and EBO(EE) (EGAAIGLAWIPYFGPAAE) sequences, which are similar to EBO(GE) except that they bear the negatively charged glutamate residue at the N terminus and at both the N and C termini, respectively, induced fusion to a lesser extent. As revealed by binding experiments, the glutamate residue at the N terminus severely impaired peptide-vesicle interaction. In addition, the fusion-competent EBO(GE) sequence did not associate significantly with vesicles lacking phosphatidylinositol. Tryptophan fluorescence quenching by vesicles containing brominated phospholipids indicated that the EBO(GE) peptide penetrated to the acyl chain level only when the membranes contained phosphatidylinositol. We conclude that binding and further penetration of the Ebola virus putative fusion peptide into membranes might be governed by the nature of the N-terminal residue and by the presence of phosphatidylinositol in the target membrane. Moreover, since insertion of such a peptide leads to membrane destabilization and fusion, the present data would be compatible with the involvement of this sequence in Ebola virus fusion.
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Affiliation(s)
- M B Ruiz-Argüello
- Grupo de Biomembranas (Unidad Asociada al CSIC), Departamento de Bioquímica, Universidad del Pais Vasco, Bilbao, Spain
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Pereira FB, Goñi FM, Muga A, Nieva JL. Permeabilization and fusion of uncharged lipid vesicles induced by the HIV-1 fusion peptide adopting an extended conformation: dose and sequence effects. Biophys J 1997; 73:1977-86. [PMID: 9336193 PMCID: PMC1181098 DOI: 10.1016/s0006-3495(97)78228-6] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The peptide HIV(arg), corresponding to a sequence of 23 amino acid residues at the N-terminus of HIV-1 gp41 (LAV1a strain), has the capacity to destabilize negatively charged large unilamellar vesicles. As revealed by infrared spectroscopy, the peptide associated with those vesicles showed conformational polymorphism: in the absence of cations the main structure was a pore-forming alpha-helix, whereas in the presence of Ca2+ the conformation switched to a fusogenic, predominantly extended beta-type structure. Here we show that an extended structure can also be involved in electrically neutral vesicle destabilization induced by the HIV-1 fusion peptide when it binds the vesicle from the aqueous phase. In the absence of cations, neutral liposomes composed of phosphatidylcholine, phosphatidylethanolamine, and cholesterol (molar ratio 1:1:1) selected for an extended structure that became fusogenic in a dose-dependent fashion. At subfusogenic doses this structure caused the release of trapped 8-aminonaphtalene-1,3,6-trisulfonic acid sodium salt/p-xylenebis(pyridinium)bromide from liposomes, indicating the existence of a peptide-mediated membrane destabilizing process before and independent of the development of fusion. When compared to HIV(arg), the fusion activity of HIV(ala) (bearing the R22 --> A substitution) was reduced by 70%. Fusogenicity was completely abolished when a second substitution (V2 --> E) was included to generate HIV(ala-E2), a sequence representing the N-terminus of an inactive gp41. However, the three sequences associated with vesicles to the same extent, and the three adopted a similar extended structure in the membrane. Whereas 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene emission anisotropy was unaffected by the three peptides, DPH emission anisotropy in membranes was increased only by the fusogenic sequences. Taken together, our observations strongly argue that it is not an alpha-helical but an extended structure adopted by the HIV-1 fusion peptide what actively destabilizes cholesterol-containing, electrically neutral membranes. Moreover, membrane destabilization is modulated by the amino acid sequence in the extended structure. The effect displayed by the aforementioned V2 --> E substitution suggests that the fusion process described here could be reflecting a physiologically relevant phenomenon.
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Affiliation(s)
- F B Pereira
- Department of Biochemistry and Molecular Biology, University of the Basque Country, Bilbao, Spain
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Pereira FB, Goñi FM, Nieva JL. Membrane fusion induced by the HIV type 1 fusion peptide: modulation by factors affecting glycoprotein 41 activity and potential anti-HIV compounds. AIDS Res Hum Retroviruses 1997; 13:1203-11. [PMID: 9310287 DOI: 10.1089/aid.1997.13.1203] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Peptides representing a sequence of 23 amino acid residues at the N terminus of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp41 bind and subsequently induce fusion of large unilamellar vesicles (LUV), an activity presumably related to gp41 function in viral infection. These in vitro effects can be modulated by several factors that are known to affect HIV-1 infectivity and gp41-mediated virus-cell fusion. Peptide-induced membrane fusion but not peptide binding can be inhibited by two factors known to block gp41 activity: a polar amino acid substitution V --> E in position 2 and the presence of the N-terminal hexapeptide of gp41 in addition to the parent sequence. Whereas inclusion of the alternative gp120 receptor galactosylceramide in membranes has virtually no effect, membrane cholesterol stimulates fusion activity. In view of its putative physiological relevance, we have used the fusion activity of the peptides as a tool to evaluate the inhibitory effect of antivirals that might target this sequence. We describe three dissimilar effects: Amphotericin B inhibits in a cholesterol-independent way peptide-induced fusion but not binding, human serum albumin inhibits binding and consequently fusion, and dextran sulfate (M(r) 5000) does not affect either binding or fusion.
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Affiliation(s)
- F B Pereira
- Department of Biochemistry and Molecular Biology (Biomembrane Laboratory-CSIC), University of the Basque Country, Bilbao, Spain
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Abstract
The 23-residue synthetic peptide representing the N-terminus of HIV-1 gp41 is known to induce either leakage or fusion of lipid vesicles depending on the experimental conditions. In this paper we report that a polar amino acid substitution V-->E at position 2, known to block gp41 activity in vivo, makes the peptide unable to destabilize and/or fuse membranes. Moreover this variant, unlike the parent peptide, is never found in the membrane-associated beta conformation.
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Affiliation(s)
- F B Pereira
- Department of Biochemistry and Molecular Biology, University of the Basque Country, Bilbao, Spain
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