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1.
Horiz. enferm ; 34(1): 90-104, 2023. tab
Artigo em Espanhol | LILACS | ID: biblio-1427989

RESUMO

OBJETIVO: Algunas investigaciones realizadas en comunidades universitarias alrededor del mundo, muestran como durante esta etapa se presentan cambios significativos frente a los estilos y dinámicas de vida los estudiantes. En este estudio se identificaron indicadores antropométricos y patrones alimentarios que caracterizan a los estudiantes universitarios de la Facultad de Ciencias de la Nutrición y los Alimentos de la Universidad CES (Colombia) en el período 2018 y 2019. MATERIALES Y MÉTODOS: Estudio retrospectivo, observacional y descriptivo, con datos provenientes de fuentes de información secundarias donde reposaba la información de los indicadores antropométricos y patrones alimentarios de los estudiantes durante el periodo en mención, las cuales fueron revisadas el primer semestre del año 2022. RESULTADOS: Tomando en cuenta el indicador de índice de masas corporal (IMC) de los evaluados, el 2,7% presento obesidad, el 18,3% sobrepeso, el 72,3 % adecuación, el 6,2 % bajo peso y un 0,4% bajo peso severo. Se encontró que los alimentos de mayor consumo diario fueron cereales refinados, raíces, plátanos y tubérculos, verduras, lácteos reducidos en grasa, carnes magras, huevos, grasas de origen vegetal y azúcares. Respecto a los alimentos con mayor consumo ocasional o sin consumo, se encuentran los cereales integrales, lácteos enteros, carnes altas en grasas, grasa de origen animal y claras de huevo. CONCLUSIONES: resultados develan que la mayor parte de los investigados reflejo un IMC normal y un menor porcentaje evidencian problemas asociados con la malnutrición, un 6,6 % presentó déficit de peso, mientras que un 21,0% presento exceso de peso, a la par se observan patrones alimentarios protectores como un elevado porcentaje de consumo diario de frutas, verduras, carnes magras, grasas de origen vegetal y consumo ocasional o no consumo de lácteos enteros, carnes altas en grasa y grasa de origen animal.


OBJECTIVE: Some investigations carried out in university communities around the world show how during this stage significant changes are presented regarding the styles and dynamics of life of the students. In this study, anthropometric indicators and eating patterns that characterize university students of the Faculty of Nutrition and Food Sciences of the CES University in the period 2018 and 2019 were identified. MATERIALS AND METHODS: Retrospective, observational and descriptive study, with data from secondary information sources where the information on the anthropometric indicators and eating patterns of the students rested during the period in question, which were reviewed the first semester of 2022. RESULTS: Taking into account the mass index indicator (BMI) of those evaluated, 2,7% present obesity, 18,3% overweight, 72,3% adequacy, 6,2% underweight and 0,4% severe underweight. It was found that the foods with the highest daily consumption were refined cereals, roots, bananas and tubers, vegetables, reduced-fat dairy products, lean meats, eggs, fats of vegetable origin, and sugars. Regarding foods with greater occasional consumption or without consumption, there are whole grains, whole milk products, high-fat meats, fat of animal origin and egg whites. CONCLUSIONS: the results reveal that the majority of those investigated reflect a normal BMI and a lower percentage show problems associated with malnutrition, 6.6% presented weight deficit, while 21,0% presented excess weight, at the same time they are observed protective food patterns such as a high percentage of daily consumption of fruits, vegetables, lean meats, fats of vegetable origin and occasional consumption or non-consumption of full-fat dairy products, meats high in fat and fat of animal origin.


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Antropometria , Estado Nutricional
2.
Mol Microbiol ; 117(1): 193-214, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34783400

RESUMO

Staphylococcus aureus RsaG is a 3'-untranslated region (3'UTR) derived sRNA from the conserved uhpT gene encoding a glucose-6-phosphate (G6P) transporter expressed in response to extracellular G6P. The transcript uhpT-RsaG undergoes degradation from 5'- to 3'-end by the action of the exoribonucleases J1/J2, which are blocked by a stable hairpin structure at the 5'-end of RsaG, leading to its accumulation. RsaG together with uhpT is induced when bacteria are internalized into host cells or in the presence of mucus-secreting cells. Using MS2-affinity purification coupled with RNA sequencing, several RNAs were identified as targets including mRNAs encoding the transcriptional factors Rex, CcpA, SarA, and the sRNA RsaI. Our data suggested that RsaG contributes to the control of redox homeostasis and adjusts metabolism to changing environmental conditions. RsaG uses different molecular mechanisms to stabilize, degrade, or repress the translation of its mRNA targets. Although RsaG is conserved only in closely related species, the uhpT 3'UTR of the ape pathogen S. simiae harbors an sRNA, whose sequence is highly different, and which does not respond to G6P levels. Our results hypothesized that the 3'UTRs from UhpT transporter encoding mRNAs could have rapidly evolved to enable adaptation to host niches.


Assuntos
Antiporters/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Pequeno RNA não Traduzido/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Fatores de Transcrição/metabolismo , Regiões não Traduzidas/genética , Adaptação Fisiológica , Antiporters/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico , Regulação Bacteriana da Expressão Gênica , Glucose-6-Fosfato/metabolismo , Homeostase , Proteínas de Transporte de Monossacarídeos/genética , Oxirredução , Estabilidade de RNA , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/fisiologia , Fatores de Transcrição/genética
3.
Front Microbiol ; 12: 706690, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367109

RESUMO

The success of the major opportunistic human Staphylococcus aureus relies on the production of numerous virulence factors, which allow rapid colonization and dissemination in any tissues. Indeed, regulation of its virulence is multifactorial, and based on the production of transcriptional factors, two-component systems (TCS) and small regulatory RNAs (sRNAs). Advances in high-throughput sequencing technologies have unveiled the existence of hundreds of potential RNAs with regulatory functions, but only a fraction of which have been validated in vivo. These discoveries have modified our thinking and understanding of bacterial physiology and virulence fitness by placing sRNAs, alongside transcriptional regulators, at the center of complex and intertwined regulatory networks that allow S. aureus to rapidly adapt to the environmental cues present at infection sites. In this review, we describe the recently acquired knowledge of characterized regulatory RNAs in S. aureus that are associated with metal starvation, nutrient availability, stress responses and virulence. These findings highlight the importance of sRNAs for the comprehension of S. aureus infection processes while raising questions about the interplay between these key regulators and the pathways they control.

4.
Vet Comp Orthop Traumatol ; 34(1): 24-31, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33058091

RESUMO

OBJECTIVE: The aim of this study was to investigate the prevalence of cranial cruciate ligament rupture and patellar luxation and the associated risk factors in dogs. MATERIALS AND METHODS: A total of 13,072 clinical records of dogs were reviewed from School Hospital (Faculty of Veterinary Sciences, National University of La Plata). Data of age, breed, sex, body weight, patellar luxation and cranial cruciate ligament rupture condition were registered. Chi-squared and Fisher's exact tests were used to compare the prevalence of cranial cruciate ligament rupture and patellar luxation with the variables and then univariable logistic regression was used to evaluate the risk of having cranial cruciate ligament rupture and patellar luxation. Multivariable logistic regression was used including all variables to assess the odds of having patellar luxation and cranial cruciate ligament rupture. RESULTS: Of 13,072 patients treated, 72 and 51 had cranial cruciate ligament rupture and patellar luxation respectively. Sex was not a major risk factor for either condition. Adult (odds ratio [OR] = 8.2) and senior (OR = 4.3) patients had increased risk of having cranial cruciate ligament rupture, while for patellar luxation age was not a risk factor. Groups 2, 3 and 8 were more likely to have cranial cruciate ligament rupture (OR = 5.5, OR = 9.1 and OR = 2.6), and group 11 had lower risk of having patellar luxation (OR = 0.08). Maxi (OR = 2.4) and giant (OR = 6.0) breeds had higher risk of having cranial cruciate ligament rupture, and medium and maxi breeds had higher risk of patellar luxation (OR = 0.05 and OR = 0.3). Multivariate OR test confirmed that age (adult), body size (giant and maxi) and breed group (Group 3) were significantly associated with having cranial cruciate ligament rupture, and age was associated with having patellar luxation. CLINICAL SIGNIFICANCE: This is the first epidemiological study of cranial cruciate ligament rupture and patellar luxation in dogs from School Hospital (Faculty of Veterinary Sciences, National University of La Plata). Giant and large adult dogs from the Molossoid and Terrier breeds were more likely to have cranial cruciate ligament rupture, while mixed and large dog breeds showed the lowest risk of having patellar luxation.


Assuntos
Lesões do Ligamento Cruzado Anterior/veterinária , Doenças do Cão/epidemiologia , Luxação Patelar/veterinária , Animais , Lesões do Ligamento Cruzado Anterior/epidemiologia , Argentina/epidemiologia , Tamanho Corporal , Estudos Transversais , Cães , Feminino , Masculino , Luxação Patelar/epidemiologia , Fatores de Risco , Ruptura/epidemiologia , Ruptura/veterinária , Especificidade da Espécie
5.
PLoS Genet ; 15(10): e1008416, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31647804

RESUMO

Laryngeal paralysis (LP) is the inability to abduct the arytenoid cartilages during inspiration, resulting in a partial to complete airway obstruction and consequent respiratory distress. Different forms of LP with varying age of onset exist in dogs. Hereditary early onset forms were reported in several dog breeds. In most breeds, hereditary LP is associated with other neurologic pathologies. Using a genome-wide association study and haplotype analyses, we mapped a major genetic risk factor for an early onset LP in Miniature Bull Terriers to a ~1.3 Mb interval on chromosome 11. Whole genome sequencing of an affected Miniature Bull Terrier and comparison to 598 control genomes revealed a 36 bp insertion into exon 15 of the RAPGEF6 gene (c.1793_1794ins36). The imperfect genotype-phenotype correlation suggested a complex mode of inheritance with a major genetic risk factor involving a recessive risk allele. Homozygosity for the insertion was associated with a 10- to 17-fold increased risk for LP. The insertion allele was only found in Miniature Bull Terriers and Bull Terriers. It was absent from >1000 control dogs of other dog breeds. The insertion sequence contains a splice acceptor motif leading to aberrant splicing in transcripts originating from the mutant allele (r.1732_1780del). This leads to a frameshift and a premature stop codon, p.(Ile587ProfsTer5), removing 64% of the open reading frame. Our results suggest an important role of RAPGEF6 in laryngeal nerve function and provide new clues to its physiological significance.


Assuntos
Doenças do Cão/genética , Predisposição Genética para Doença , Fatores de Troca do Nucleotídeo Guanina/genética , Paralisia das Pregas Vocais/genética , Animais , Cartilagem Aritenoide/patologia , Cruzamento , Códon sem Sentido/genética , Doenças do Cão/fisiopatologia , Cães , Éxons , Mutação da Fase de Leitura/genética , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Nervos Laríngeos/patologia , Splicing de RNA/genética , Paralisia das Pregas Vocais/fisiopatologia , Paralisia das Pregas Vocais/veterinária , Sequenciamento Completo do Genoma
7.
J Vet Diagn Invest ; 30(2): 310-314, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29271313

RESUMO

von Willebrand disease (vWD) is the most common inherited coagulopathy in dogs, particularly in Doberman Pinschers. We developed a pyrosequencing-based assay to estimate the frequency of the c.7437G>A mutation associated with vWD type 1 in the Doberman Pinscher population of Buenos Aires, Argentina. We found a 0.41 frequency for the mutated allele, which varied significantly within families (family 1 = 0.43, family 2 = 0.58, unrelated animals = 0.35). The use of a popular founder male carrier of mutant allele A increased vWD incidence within a family and in the general population. The mode of inheritance was confirmed as autosomal dominant with incomplete penetrance. No differences were found between sexes and coat colors. Pyrosequencing was a good complement to clinical and coagulation tests for vWD type 1 diagnosis and a useful alternative for detecting the c.7437G>A mutation.


Assuntos
Doenças do Cão/epidemiologia , Doenças de von Willebrand/veterinária , Fator de von Willebrand/genética , Animais , Argentina/epidemiologia , Doenças do Cão/genética , Cães , Feminino , Genótipo , Masculino , Mutação , Linhagem , Prevalência , Doenças de von Willebrand/epidemiologia
8.
Vet Immunol Immunopathol ; 156(3-4): 205-10, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24238945

RESUMO

Canine chronic superficial keratitis (CSK) is an inflammatory corneal disease that primarily occurs in German shepherd dogs (GSDs). Several studies support the hypothesis that CSK is an immune-mediated disease. To investigate the genetic factors associated with CSK development, the upstream regulatory regions (URRs) of the DLA-DRB, -DQA and -DQB genes were genotyped in 60 dogs, including 32 CSK animals. LD analysis identified two blocks (r(2)≤45), with two DLA-DRB1 and five DLA-DQB1 haplotypes. Analysis of DLA-URR alleles/haplotypes showed a significant association between DQB1*-154 [C/T] (p=0.016) and CSK, suggesting that the T variant may increase the risk for developing CSK disease (OR=3, 95% CI=1.25-7.68). When haplotype associations were performed, the URR-DQB*CATT haplotype was significantly associated with CSK (p=0.016), increasing the risk of develop this disease over two-fold (OR=3, 95%, CI=1.25-7.68). These results showed that dogs homozygous at DRB1*69 [C/T] had a risk for developing CSK disease that was over four times the risk for heterozygotes. This genetic association supports the previous clinical, histological and pharmacological studies that suggest that CSK is an immune-mediated disease, and this association could potentially be used to identify susceptible animals.


Assuntos
Doenças do Cão/imunologia , Cadeias alfa de HLA-DQ/genética , Cadeias beta de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Ceratite/veterinária , Polimorfismo de Nucleotídeo Único , Sequências Reguladoras de Ácido Nucleico , Animais , Doença Crônica , Doenças do Cão/genética , Cães , Feminino , Ceratite/imunologia , Masculino
9.
J Infect Dis ; 196 Suppl 2: S220-31, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17940953

RESUMO

Milligram quantities of Zaire ebolavirus nonstructural, secreted glycoprotein (sGP) were purified to homogeneity, and this preparation was characterized by an array of biophysical and biochemical experiments. Mass-spectrometry analysis revealed sGP posttranslational modifications and regions susceptible to limited proteolysis. In solution, sGP has an absolute molar mass of 103 kDa, is monodisperse, and folds into a predominantly beta -sheet conformation with a distinct tertiary structure. sGP appears to have a unique free-energy landscape that facilitates reversible folding and a strong propensity for disulfide-linked dimeric quaternary structure under a wide range of conditions; the low apparent free energy of conformation transition of sGP ( Delta G=1.7+/-0.1 kcal/mol) suggests that the molecule is well suited as a thermodynamically facile switch, which would allow it to report on relatively subtle changes in milieu. In addition, a conformational transition at 37 degrees C was detected in thermal denaturing experiments. On the basis of biophysical and biochemical considerations alone, we propose that the property of being a thermodynamically facile switch is an important clue to reveal sGP functionality.


Assuntos
Ebolavirus/fisiologia , Glicoproteínas/química , Glicoproteínas/metabolismo , Proteínas Virais/química , Proteínas Virais/metabolismo , Animais , Fenômenos Biofísicos , Biofísica , Chlorocebus aethiops , República Democrática do Congo , Estabilidade de Medicamentos , Ebolavirus/isolamento & purificação , Haplorrinos , Conformação Proteica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Termodinâmica , Células Vero
10.
Virology ; 358(1): 1-9, 2007 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-16982079

RESUMO

Ebola virus is highly cytopathic through mechanisms that are largely unknown. We present evidence that progressive acidification of the extracellular milieu by Ebola virus-infected cells combined with reduced levels of natural cysteine protease inhibitor makes the cells vulnerable to uncontrolled proteolysis of extracellular matrix components by released active endosomal cathepsins, thereby exacerbating Ebola virus-induced cell destruction. The cell surface microenvironment was shown to be crucial in aiding this activity. Blocking the proteolytic activity with the cathepsin inhibitor E64 resulted in remarkable improvements with respect to viral cytopathicity and cell survival despite an overwhelmingly high viral load. We propose that the observed enzymatic matrix degradation, enhanced by an associated protease/inhibitor imbalance and metabolic acidosis, represents an effective viral strategy to boost infection and underlies, in part, the remarkable pathogenesis caused by Ebola virus. Further in vitro and in vivo research will establish whether a cellular protease with hemorrhagic activity is the leading cause of vascular leakage-the hallmark of Ebola virus hemorrhagic fever-and help understand the Ebola virus caused cell death.


Assuntos
Catepsinas/metabolismo , Efeito Citopatogênico Viral , Ebolavirus/patogenicidade , Animais , Catepsinas/antagonistas & inibidores , Sobrevivência Celular , Chlorocebus aethiops , Meios de Cultivo Condicionados/química , Inibidores de Cisteína Proteinase/farmacologia , Concentração de Íons de Hidrogênio , Microscopia , Células Vero
11.
Protein Eng Des Sel ; 19(12): 525-35, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17012344

RESUMO

The HIV-inactivating protein Cyanovirin-N (CV-N) is a cyanobacterial lectin that exhibits potent antiviral activity at nanomolar concentrations by interacting with high-mannose carbohydrates on viral glycoproteins. To date there is no molecular explanation for this potent virucidal activity, given the experimentally measured micromolar affinities for small sugars and the problems encountered with aggregation and precipitation of high-mannose/CV-N complexes. Here, we present results for two CV-N variants, CV-N(mutDA) and CV-N(mutDB), compare their binding properties with monomeric [P51G]CV-N (a stabilized version of wtCV-N) and test their in vitro activities. The mutations in CV-N(mutDA) and CV-N(mutDB) comprise changes in amino acids that alter the trimannose specificity of domain A(M) and abolish the sugar binding site on domain B(M), respectively. We demonstrate that carbohydrate binding via domain B(M) is essential for antiviral activity, whereas alterations in sugar binding specificity on domain A(M) have little effect on envelope glycoprotein recognition and antiviral activity. Changes in A(M), however, affect the cross-linking activity of CV-N. Our findings augment and clarify the existing models of CV-N binding to N-linked glycans on viral glycoproteins, and demonstrate that the nanomolar antiviral potency of CV-N is related to the constricted and spatially crowded arrangement of the mannoses in the glycan clusters on viral glycoproteins and not due to CV-N induced virus particle agglutination, making CV-N a true viral entry inhibitor.


Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/farmacologia , Proteínas de Transporte/química , Proteínas de Transporte/farmacologia , HIV-1/efeitos dos fármacos , Mutagênese Sítio-Dirigida , Internalização do Vírus/efeitos dos fármacos , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sítios de Ligação , Sequência de Carboidratos , Proteínas de Transporte/genética , Proteína gp120 do Envelope de HIV/química , HIV-1/química , HIV-1/fisiologia , Humanos , Células Jurkat , Manose , Lectinas de Ligação a Manose/química , Lectinas de Ligação a Manose/genética , Lectinas de Ligação a Manose/farmacologia , Manosídeos/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia
12.
Mini Rev Med Chem ; 5(1): 21-31, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15638789

RESUMO

Cyanovirin-N (CV-N), a cyanobacterial lectin, is a potent viral entry inhibitor currently under development as a microbicide against a broad spectrum of enveloped viruses. CV-N was originally identified as a highly active anti-HIV agent and later, as a virucidal agent against other unrelated enveloped viruses such as Ebola, and possibly other viruses. CV-N's antiviral activity appears to involve unique recognition of N-linked high-mannose oligosaccharides, Man-8 and Man-9, on the viral surface glycoproteins. Due to its distinct mode of action and opportunities for harnessing the associated interaction for therapeutic intervention, a substantial body of research on CV-N has accumulated since its discovery in 1997. In this review we focus in particular on structural studies on CV-N and their relationship to biological activity.


Assuntos
Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Proteínas de Bactérias/farmacologia , Proteínas de Bactérias/uso terapêutico , Proteínas de Transporte/farmacologia , Proteínas de Transporte/uso terapêutico , Infecções por HIV/tratamento farmacológico , Doença pelo Vírus Ebola/tratamento farmacológico , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/química , Proteínas de Transporte/química , HIV-1/efeitos dos fármacos , HIV-1/patogenicidade , Humanos , Dados de Sequência Molecular
13.
Structure ; 12(10): 1799-807, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15458629

RESUMO

Cyanovirin-N can exist in solution in monomeric and domain-swapped dimeric forms, with HIV-antiviral activity being reported for both. Here we present results for CV-N variants that form stable solution dimers: the obligate dimer [DeltaQ50]CV-N and the preferential dimer [S52P]CV-N. These variants exhibit comparable DeltaG values (10.6 +/- 0.5 and 9.4 +/- 0.5 kcal.mol(-1), respectively), similar to that of stabilized, monomeric [P51G]CV-N (9.8 +/- 0.5 kcal.mol(-1)), but significantly higher than wild-type CV-N (4.1 +/- 0.2 kcal.mol(-1)). During folding/unfolding, no stably folded monomer was observed under any condition for the obligate dimer [DeltaQ50]CV-N, whereas two monomeric, metastable species were detected for [S52P]CV-N at low concentrations. This is in contrast to our previous results for [P51G]CV-N and wild-type CV-N, for which the dimeric forms were found to be the metastable species. The dimeric mutants exhibit comparable antiviral activity against HIV and Ebola, similar to that of wild-type CV-N and the stabilized [P51G]CV-N variant.


Assuntos
Antivirais/química , Antivirais/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/farmacologia , Proteínas de Transporte/química , Proteínas de Transporte/farmacologia , Substituição de Aminoácidos/genética , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Proteínas de Bactérias/genética , Bioensaio , Proteínas de Transporte/genética , Dimerização , Ebolavirus/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Mutação/genética , Dobramento de Proteína , Estrutura Terciária de Proteína , Termodinâmica
14.
Biochem Biophys Res Commun ; 323(2): 696-702, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15369806

RESUMO

The non-structural glycoprotein (SGP) of Ebola virus (EboV) is secreted in large amounts from infected cells as a disulfide-linked homodimer. In this communication, highly purified SGP, derived from Vero E6 cultures infected with the Zaire species of EboV, was used to determine the correct localization of inter- and intrachain disulfide bonds. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis of proteolytic cleavage fragments indicates that all cysteines (six per monomeric unit) form unique disulfide bonds. Monomers of the SGP homodimer are joined in a parallel manner by two intersubunit disulfide bonds formed between paired N-terminal and C-terminal cysteines (C53-C53' and C306-C306'). The remaining cysteines are involved in intrachain disulfide bonding (paired as C108-C135 and C121-C147), which resembles the disulfide bond topology of fibronectin type II domains. The findings presented here provide the foundation for future studies aimed at defining the structural and functional properties of SGP.


Assuntos
Cisteína/química , Dissulfetos/química , Ebolavirus/metabolismo , Glicoproteínas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Proteínas Virais/química , Sequência de Aminoácidos , Sítios de Ligação , Dimerização , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica
15.
J Infect Dis ; 189(8): 1440-3, 2004 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15073681

RESUMO

Cyanovirin-N (CV-N) has been shown to inhibit Ebola Zaire virus (EboZV) infection, both in vitro and in vivo, through its ability to bind to oligomannoses-8/9 on the EboZV surface glycoprotein (GP). Here, we report the in vitro potency of CV-N to inhibit EboZV GP- and Marburg virus GP-pseudotyped viruses (EC50 approximately 40-60 nmol/L and approximately 6-25 nmol/L, respectively) from mediating gene transduction into HeLa cells. In addition, we provide evidence that CV-N can effectively inhibit DC-SIGN-mediated EboZV infection. Our data emphasize both the utility of GP-pseudotyped vectors in the assessment of compounds that affect cell entry by filovirus and the use of CV-N as a reagent for the probing of carbohydrate-dependent interactions at viral entry.


Assuntos
Antivirais/farmacologia , Proteínas de Bactérias , Proteínas de Transporte/farmacologia , Ebolavirus/efeitos dos fármacos , Doença pelo Vírus Ebola/prevenção & controle , Doença do Vírus de Marburg/tratamento farmacológico , Marburgvirus/efeitos dos fármacos , Proteínas Virais , Ebolavirus/metabolismo , Glicoproteínas/antagonistas & inibidores , Glicoproteínas/metabolismo , Células HeLa , Doença pelo Vírus Ebola/virologia , Humanos , Células Jurkat , Lentivirus/metabolismo , Doença do Vírus de Marburg/virologia , Marburgvirus/metabolismo , Transdução Genética , Replicação Viral/efeitos dos fármacos
16.
Antiviral Res ; 58(1): 47-56, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12719006

RESUMO

Ebola virus (Ebo) causes severe hemorrhagic fever and high mortality in humans. There are currently no effective therapies. Here, we have explored potential anti-Ebo activity of the human immunodeficiency virus (HIV)-inactivating protein cyanovirin-N (CV-N). CV-N is known to potently inhibit the infectivity of a broad spectrum of HIV strains at the level of viral entry. This involves CV-N binding to N-linked high-mannose oligossacharides on the viral glycoprotein gp120. The Ebola envelope contains somewhat similar oligosaccharide constituents, suggesting possible susceptibility to inhibition by CV-N. Our initial results revealed that CV-N had both in vitro and in vivo antiviral activity against the Zaire strain of the Ebola virus (Ebo-Z). Addition of CV-N to the cell culture medium at the time of Ebo-Z infection inhibited the development of viral cytopathic effects (CPEs). CV-N also delayed the death of Ebo-Z-infected mice, both when given as a series of daily subcutaneous injections and when the virus was incubated ex vivo together with CV-N before inoculation into the mice. Furthermore, similar to earlier results with HIV gp120, CV-N bound with considerable affinity to the Ebola surface envelope glycoprotein, GP(1,2). Competition experiments with free oligosaccharides were consistent with the view that carbohydrate-mediated CV-N/GP(1,2) interactions involve oligosaccharides residing on the Ebola viral envelope. Overall, these studies broaden the range of viruses known to be inhibited by CV-N, and further implicate carbohydrate moieties on viral surface proteins as common viral molecular targets for this novel protein.


Assuntos
Antivirais/farmacologia , Proteínas de Bactérias , Proteínas de Transporte/farmacologia , Ebolavirus/efeitos dos fármacos , Doença pelo Vírus Ebola/tratamento farmacológico , Animais , Antivirais/metabolismo , Western Blotting , Proteínas de Transporte/metabolismo , Chlorocebus aethiops , Efeito Citopatogênico Viral/efeitos dos fármacos , Ebolavirus/metabolismo , Ebolavirus/patogenicidade , Ensaio de Imunoadsorção Enzimática , Feminino , Glicoproteínas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Células Vero , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacos
17.
J Mol Biol ; 325(1): 211-23, 2003 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-12473463

RESUMO

The high-resolution solution structure of a monomeric circular permuted (cp) variant of the potent HIV-inactivating protein cyanovirin-N (CV-N) was determined by NMR. Comparison with the wild-type (wt) structure revealed that the observed loss in stability of cpCV-N compared to the wt protein is due to less favorable packing of several residues at the pseudo twofold axis that are responsible for holding the two halves of the molecule together. In particular, the N and C-terminal amino acid residues exhibit conformational flexibility, resulting in fewer and less favorable contacts between them. The important hydrophobic and hydrogen-bonding network between residues W49, D89, H90, Y100 and E101 that was observed in wt CV-N is no longer present. For instance, Y100 and E101 are flexible and the tryptophan side-chain is in a different conformation compared to the wt protein. The stability loss amounts to approximately 2kcal/mol and the mobility of the protein is evident by fast amide proton exchange throughout the chain. Mutation of the single proline residue to glycine (P52G) did not substantially affect the stability of the protein, in contrast to the finding for wtCV-N. The binding of high-mannose type oligosaccharides to cpCV-N was also investigated. Similar to wtCV-N, two carbohydrate-binding sites were identified on the protein and the Man alpha1-->2Man linked moieties on the sugar were delineated as binding epitopes. Unlike in wtCV-N, the binding sites on cpCV-N are structurally similar and exhibit comparable binding affinities for the respective sugars. On the basis of the studies presented here and previous results on high-mannose binding to wtCV-N, we discuss a model for the interaction between gp120 and CV-N.


Assuntos
Proteínas de Bactérias , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Engenharia Genética , Ressonância Magnética Nuclear Biomolecular , Oligossacarídeos/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Proteínas de Transporte/genética , Dicroísmo Circular , Proteína gp120 do Envelope de HIV/química , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Manose/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Oligossacarídeos/química , Prolina/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Soluções/química , Relação Estrutura-Atividade , Especificidade por Substrato
18.
Biochem Biophys Res Commun ; 298(4): 598-602, 2002 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-12408994

RESUMO

The binding of high-mannose oligosaccharides to the domain-swapped dimeric form of the potent HIV-inactivating protein cyanovirin-N (CV-N) was investigated in solution by NMR, complementing recent structural studies by X-ray crystallography on similar complexes [J. Biol. Chem. 277 (2002) 34336]. The crystal structures of CV-N dimer complexed with Man-9 and hexamannoside revealed two carbohydrate binding sites on opposite ends of the molecule. No binding was observed at site 1, previously identified on the solution monomer of CV-N [Structure 9 (2001) 931; Shenoy et al., Chem. Biol. 9 (2002) 1109]. Here, we report the presence of four sugar binding sites on the CV-N dimer in solution, identified by chemical shift mapping with hexamannoside and nonamannoside, synthetic substructures of Man-9. Our results demonstrate that in solution the domain-swapped CV-N dimer, like the CV-N monomer, contains two types of sites that are available for carbohydrate binding, suggesting that the occlusion of the primary sites in the crystal is due to specific features of the solid state.


Assuntos
Proteínas de Bactérias , Proteínas de Transporte/metabolismo , Oligossacarídeos/metabolismo , Sítios de Ligação , Proteínas de Transporte/química , Cristalografia por Raios X , Dimerização , Ressonância Magnética Nuclear Biomolecular , Soluções
19.
Chem Biol ; 9(10): 1109-18, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12401495

RESUMO

Binding of the protein cyanovirin-N to oligomannose-8 and oligomannose-9 of gp120 is crucially involved in its potent virucidal activity against the human immunodeficiency virus (HIV). The interaction between cyanovirin-N and these oligosaccharides has not been thoroughly characterized due to aggregation of the oligosaccharide-protein complexes. Here, cyanovirin-N's interaction with a nonamannoside, a structural analog of oligomannose-9, has been studied by nuclear magnetic resonance and isothermal titration calorimetry. The nonamannoside interacts with cyanovirin-N in a multivalent fashion, resulting in tight complexes with an average 1:1 stoichiometry. Like the nonamannoside, an alpha1-->2-linked trimannoside substructure interacts with cyanovirin-N at two distinct protein subsites. The chitobiose and internal core trimannoside substructures of oligomannose-9 are not recognized by cyanovirin-N, and binding of the core hexamannoside occurs at only one of the sites on the protein. This is the first detailed analysis of a biologically relevant interaction between cyanovirin-N and high-mannose oligosaccharides of HIV-1 gp120.


Assuntos
Proteínas de Bactérias , Proteínas de Transporte/química , Oligossacarídeos/química , Sítios de Ligação , Calorimetria , Proteínas de Transporte/metabolismo , Dissacarídeos/química , Dissacarídeos/metabolismo , Humanos , Modelos Biológicos , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Oligossacarídeos/metabolismo , Ligação Proteica , Termodinâmica
20.
Protein Expr Purif ; 26(1): 42-9, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12356469

RESUMO

Cyanovirin-N (CV-N) is under development as a topical (vaginal or rectal) microbicide to prevent sexual transmission of human immunodeficiency virus (HIV), and an economically feasible means for very large-scale production of the protein is an urgent priority. We observed that N-glycosylation of CV-N in yeast eliminated the anti-HIV activity, and that dimeric forms and aggregates of CV-N occurred under certain conditions, potentially complicating the efficient, large-scale manufacture of pure monomeric CV-N. We therefore expressed and tested CV-N homologs in which the glycosylation-susceptible Asn residue at position 30 was replaced with Ala, Gln, or Val, and/or the Pro at position 51 was replaced by Gly to eliminate potential conformational heterogeneity. All homologs exhibited anti-HIV activity comparable to wild-type CV-N, and the Pro51Gly homologs were significantly more stable proteins. These glycosylation-resistant, functional cyanovirins should be amenable to large-scale production either in bacteria or in eukaryotic hosts.


Assuntos
Substituição de Aminoácidos/genética , Proteínas de Transporte/biossíntese , Proteínas de Transporte/farmacologia , Pichia/genética , Amidoidrolases/metabolismo , Sequência de Aminoácidos , Fármacos Anti-HIV/química , Fármacos Anti-HIV/isolamento & purificação , Fármacos Anti-HIV/metabolismo , Fármacos Anti-HIV/farmacologia , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Proteínas de Transporte/química , Proteínas de Transporte/genética , Eletroforese em Gel de Poliacrilamida , Células Eucarióticas , Glicosilação , HIV-1/efeitos dos fármacos , Dados de Sequência Molecular , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase , Células Procarióticas , Desnaturação Proteica , Temperatura , Termodinâmica , Transformação Genética
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