Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects
Autor(a) principal: | |
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Data de Publicação: | 2005 |
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/10198/3944 |
Resumo: | We performed a comparative study on the activity of Fusarium solani pisi cutinase immobilized on zeolites NaA and NaY, in n-hexane, acetonitrile, supercritical ethane (sc-ethane) and sc-CO2, at two different water activity (aW) values set by salt hydrate pairs in situ and at acid–base conditions fixed with solid-state buffers of aqueous pKa between 4.3 and 10.6. The reaction studied was the transesterification of vinyl butyrate by (R,S)-2-phenyl-1-propanol. The transesterification activity of cutinase was highest and similar in sc-ethane and in n-hexane,about one order of magnitude lower in acetonitrile and even lower in sc-CO2. Activity coefficients (γ) generated for the two substrates indicated that they were better solvated in acetonitrile and thus less available for binding at the active site than in the other three solvents. γ data also suggested higher reaction rates in sc-ethane than in n-hexane, as observed, and provided evidence for a direct negative effect of sc-CO2 on enzyme activity. Manipulation of the acid–base conditions of the media did not afford any improvement of the initial rates of transesterification relative to the blanks (no added acid–base buffer, only salt hydrate pair), except in the case of cutinase immobilized on zeolite NaA in sc-ethane at aW = 0.7. The poor performance of the blank in this case and the great improvement observed in the presence of a basic buffer suggest a deleterious acidic effect in the medium which, an experiment without additives confirmed, was not due to the known acidic character of the salt hydrate pair used to set aW = 0.7. In acetonitrile, increasing aW was accompanied by a decrease in initial rates of transesterification, unlike in the other solvents. There was considerable hydrolysis in acetonitrile, where initial rates of hydrolysis increased about 20-fold from aW = 0.2 to 0.7. Hydrolysis was less pronounced in sc-ethane and in n-hexane, and only at aW = 0.7, and in sc-CO2 butyric acid was detected only at very long reaction times, in agreement with a generally low catalytic activity. Cutinase enantio-selectivity towards the alcohol substrate was low and unaffected by any manipulation of medium conditions. |
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Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effectsWe performed a comparative study on the activity of Fusarium solani pisi cutinase immobilized on zeolites NaA and NaY, in n-hexane, acetonitrile, supercritical ethane (sc-ethane) and sc-CO2, at two different water activity (aW) values set by salt hydrate pairs in situ and at acid–base conditions fixed with solid-state buffers of aqueous pKa between 4.3 and 10.6. The reaction studied was the transesterification of vinyl butyrate by (R,S)-2-phenyl-1-propanol. The transesterification activity of cutinase was highest and similar in sc-ethane and in n-hexane,about one order of magnitude lower in acetonitrile and even lower in sc-CO2. Activity coefficients (γ) generated for the two substrates indicated that they were better solvated in acetonitrile and thus less available for binding at the active site than in the other three solvents. γ data also suggested higher reaction rates in sc-ethane than in n-hexane, as observed, and provided evidence for a direct negative effect of sc-CO2 on enzyme activity. Manipulation of the acid–base conditions of the media did not afford any improvement of the initial rates of transesterification relative to the blanks (no added acid–base buffer, only salt hydrate pair), except in the case of cutinase immobilized on zeolite NaA in sc-ethane at aW = 0.7. The poor performance of the blank in this case and the great improvement observed in the presence of a basic buffer suggest a deleterious acidic effect in the medium which, an experiment without additives confirmed, was not due to the known acidic character of the salt hydrate pair used to set aW = 0.7. In acetonitrile, increasing aW was accompanied by a decrease in initial rates of transesterification, unlike in the other solvents. There was considerable hydrolysis in acetonitrile, where initial rates of hydrolysis increased about 20-fold from aW = 0.2 to 0.7. Hydrolysis was less pronounced in sc-ethane and in n-hexane, and only at aW = 0.7, and in sc-CO2 butyric acid was detected only at very long reaction times, in agreement with a generally low catalytic activity. Cutinase enantio-selectivity towards the alcohol substrate was low and unaffected by any manipulation of medium conditions.This work has been supported by Fundação para a Ciência e Tecnologia (FCT, Portugal) through the contracts PRAXIS/PBIO/14314/1998 and POCTI/35429/QUI/2000 and the grant PRAXIS XXI/BD/21615/99 (S. Garcia), and by FEDER.We thank Ricardo Baptista for help in the production of cutinase.ElsevierBiblioteca Digital do IPBGarcía, Sílvia D.Vidinha, PedroArvana, HelenaSilva, Marco D.R. Gomes daFerreira, OlgaCabral, Joaquim M.S.Macedo, Eugénia A.Harper, NeilBarreiros, Susana F.2011-04-04T16:13:59Z20052005-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10198/3944engGarcia, Sílvia; Vidinha, Pedro; Arvana, Helena; Gomes da Silva, Marco D.R.; Macedo, Eugénia A.; Harper, Neil; Barreiros, Susana (2005). Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects. Journal of Supercritical Fluids. ISSN 0896-8446. p.62-650896-844610.1016/j.supflu.2004.10.0111872-8162info: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:RCAAP2023-11-21T10:10:04Zoai:bibliotecadigital.ipb.pt:10198/3944Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T22:56:36.300216Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
title |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
spellingShingle |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects García, Sílvia D. |
title_short |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
title_full |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
title_fullStr |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
title_full_unstemmed |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
title_sort |
Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects |
author |
García, Sílvia D. |
author_facet |
García, Sílvia D. Vidinha, Pedro Arvana, Helena Silva, Marco D.R. Gomes da Ferreira, Olga Cabral, Joaquim M.S. Macedo, Eugénia A. Harper, Neil Barreiros, Susana F. |
author_role |
author |
author2 |
Vidinha, Pedro Arvana, Helena Silva, Marco D.R. Gomes da Ferreira, Olga Cabral, Joaquim M.S. Macedo, Eugénia A. Harper, Neil Barreiros, Susana F. |
author2_role |
author author author author author author author author |
dc.contributor.none.fl_str_mv |
Biblioteca Digital do IPB |
dc.contributor.author.fl_str_mv |
García, Sílvia D. Vidinha, Pedro Arvana, Helena Silva, Marco D.R. Gomes da Ferreira, Olga Cabral, Joaquim M.S. Macedo, Eugénia A. Harper, Neil Barreiros, Susana F. |
description |
We performed a comparative study on the activity of Fusarium solani pisi cutinase immobilized on zeolites NaA and NaY, in n-hexane, acetonitrile, supercritical ethane (sc-ethane) and sc-CO2, at two different water activity (aW) values set by salt hydrate pairs in situ and at acid–base conditions fixed with solid-state buffers of aqueous pKa between 4.3 and 10.6. The reaction studied was the transesterification of vinyl butyrate by (R,S)-2-phenyl-1-propanol. The transesterification activity of cutinase was highest and similar in sc-ethane and in n-hexane,about one order of magnitude lower in acetonitrile and even lower in sc-CO2. Activity coefficients (γ) generated for the two substrates indicated that they were better solvated in acetonitrile and thus less available for binding at the active site than in the other three solvents. γ data also suggested higher reaction rates in sc-ethane than in n-hexane, as observed, and provided evidence for a direct negative effect of sc-CO2 on enzyme activity. Manipulation of the acid–base conditions of the media did not afford any improvement of the initial rates of transesterification relative to the blanks (no added acid–base buffer, only salt hydrate pair), except in the case of cutinase immobilized on zeolite NaA in sc-ethane at aW = 0.7. The poor performance of the blank in this case and the great improvement observed in the presence of a basic buffer suggest a deleterious acidic effect in the medium which, an experiment without additives confirmed, was not due to the known acidic character of the salt hydrate pair used to set aW = 0.7. In acetonitrile, increasing aW was accompanied by a decrease in initial rates of transesterification, unlike in the other solvents. There was considerable hydrolysis in acetonitrile, where initial rates of hydrolysis increased about 20-fold from aW = 0.2 to 0.7. Hydrolysis was less pronounced in sc-ethane and in n-hexane, and only at aW = 0.7, and in sc-CO2 butyric acid was detected only at very long reaction times, in agreement with a generally low catalytic activity. Cutinase enantio-selectivity towards the alcohol substrate was low and unaffected by any manipulation of medium conditions. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005 2005-01-01T00:00:00Z 2011-04-04T16:13:59Z |
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/10198/3944 |
url |
http://hdl.handle.net/10198/3944 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Garcia, Sílvia; Vidinha, Pedro; Arvana, Helena; Gomes da Silva, Marco D.R.; Macedo, Eugénia A.; Harper, Neil; Barreiros, Susana (2005). Cutinase activity in supercritical and organic media: water activity, solvation and acid–base effects. Journal of Supercritical Fluids. ISSN 0896-8446. p.62-65 0896-8446 10.1016/j.supflu.2004.10.011 1872-8162 |
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info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
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reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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