A common mechanism for influenza virus fusion activity and inactivation
Autor(a) principal: | |
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Data de Publicação: | 1993 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/10480 https://doi.org/10.1021/bi00062a006 |
Resumo: | The fusion of influenza virus (A/PR/8/34 strain) with PC- 12 cells was monitored by a fluorescence assay, and the results were analyzed with a mass-action model which could explain and predict the kinetics of fusion. The model accounted explicitly for the reduction in the fusion rate constant upon exposure of the virus to low pH, either for the virus alone in suspension or for the virus bound to the cells. When the pH was lowered without previous viral attachment to cells, an optimal fusion activity was detected at pH 5.2. When the virus was prebound to the cells, however, reduction of pH below 5.2 resulted in enhanced fusion activity at the initial stages. These results were explained by the fact that the rate constants of both fusion and inactivation increased severalfold at pH 4.5 or 4, compared to those at pH 5.2. At pH 5.2, lowering the temperature from 37 to 20 or 4 "C resulted in a decrease in the fusion rate constant by more than 30- or 1000-fold, respectively. Inactivation of the virus when preincubated in the absence of target membranes at pH 5 was found to be rapid and extensive at 37 OC, but was also detected at 0 OC. Our results indicate a strong correlation between fusion and inactivation rate constants, suggesting that the rate-limiting step in viral hemagglutinin (HA)-mediated fusion, that is, rearrangement of viral glycoproteins at the contact points with the target membrane, is similar to that involved in fusion inactivation. |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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A common mechanism for influenza virus fusion activity and inactivationThe fusion of influenza virus (A/PR/8/34 strain) with PC- 12 cells was monitored by a fluorescence assay, and the results were analyzed with a mass-action model which could explain and predict the kinetics of fusion. The model accounted explicitly for the reduction in the fusion rate constant upon exposure of the virus to low pH, either for the virus alone in suspension or for the virus bound to the cells. When the pH was lowered without previous viral attachment to cells, an optimal fusion activity was detected at pH 5.2. When the virus was prebound to the cells, however, reduction of pH below 5.2 resulted in enhanced fusion activity at the initial stages. These results were explained by the fact that the rate constants of both fusion and inactivation increased severalfold at pH 4.5 or 4, compared to those at pH 5.2. At pH 5.2, lowering the temperature from 37 to 20 or 4 "C resulted in a decrease in the fusion rate constant by more than 30- or 1000-fold, respectively. Inactivation of the virus when preincubated in the absence of target membranes at pH 5 was found to be rapid and extensive at 37 OC, but was also detected at 0 OC. Our results indicate a strong correlation between fusion and inactivation rate constants, suggesting that the rate-limiting step in viral hemagglutinin (HA)-mediated fusion, that is, rearrangement of viral glycoproteins at the contact points with the target membrane, is similar to that involved in fusion inactivation.American Chemical Society1993-03info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/10480http://hdl.handle.net/10316/10480https://doi.org/10.1021/bi00062a006engBiochemistry. 32:11 (1993) 2771-27790006-2960Ramalho-Santos, JoãoNir, ShlomoDüzgünes, NejatCarvalho, Arsélio Pato deLima, Maria da Conceição Pedroso deinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2020-05-29T09:41:56ZPortal AgregadorONG |
dc.title.none.fl_str_mv |
A common mechanism for influenza virus fusion activity and inactivation |
title |
A common mechanism for influenza virus fusion activity and inactivation |
spellingShingle |
A common mechanism for influenza virus fusion activity and inactivation Ramalho-Santos, João |
title_short |
A common mechanism for influenza virus fusion activity and inactivation |
title_full |
A common mechanism for influenza virus fusion activity and inactivation |
title_fullStr |
A common mechanism for influenza virus fusion activity and inactivation |
title_full_unstemmed |
A common mechanism for influenza virus fusion activity and inactivation |
title_sort |
A common mechanism for influenza virus fusion activity and inactivation |
author |
Ramalho-Santos, João |
author_facet |
Ramalho-Santos, João Nir, Shlomo Düzgünes, Nejat Carvalho, Arsélio Pato de Lima, Maria da Conceição Pedroso de |
author_role |
author |
author2 |
Nir, Shlomo Düzgünes, Nejat Carvalho, Arsélio Pato de Lima, Maria da Conceição Pedroso de |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Ramalho-Santos, João Nir, Shlomo Düzgünes, Nejat Carvalho, Arsélio Pato de Lima, Maria da Conceição Pedroso de |
description |
The fusion of influenza virus (A/PR/8/34 strain) with PC- 12 cells was monitored by a fluorescence assay, and the results were analyzed with a mass-action model which could explain and predict the kinetics of fusion. The model accounted explicitly for the reduction in the fusion rate constant upon exposure of the virus to low pH, either for the virus alone in suspension or for the virus bound to the cells. When the pH was lowered without previous viral attachment to cells, an optimal fusion activity was detected at pH 5.2. When the virus was prebound to the cells, however, reduction of pH below 5.2 resulted in enhanced fusion activity at the initial stages. These results were explained by the fact that the rate constants of both fusion and inactivation increased severalfold at pH 4.5 or 4, compared to those at pH 5.2. At pH 5.2, lowering the temperature from 37 to 20 or 4 "C resulted in a decrease in the fusion rate constant by more than 30- or 1000-fold, respectively. Inactivation of the virus when preincubated in the absence of target membranes at pH 5 was found to be rapid and extensive at 37 OC, but was also detected at 0 OC. Our results indicate a strong correlation between fusion and inactivation rate constants, suggesting that the rate-limiting step in viral hemagglutinin (HA)-mediated fusion, that is, rearrangement of viral glycoproteins at the contact points with the target membrane, is similar to that involved in fusion inactivation. |
publishDate |
1993 |
dc.date.none.fl_str_mv |
1993-03 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/10480 http://hdl.handle.net/10316/10480 https://doi.org/10.1021/bi00062a006 |
url |
http://hdl.handle.net/10316/10480 https://doi.org/10.1021/bi00062a006 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Biochemistry. 32:11 (1993) 2771-2779 0006-2960 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
American Chemical Society |
publisher.none.fl_str_mv |
American Chemical Society |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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_version_ |
1777302656260243456 |