Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L.
Autor(a) principal: | |
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Data de Publicação: | 1996 |
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/10316/8139 https://doi.org/10.1111/j.1432-1033.1996.00762.x |
Resumo: | Two new aspartic proteinases have been isolated from stigmas of the cardoon Cynara cardunculus L. by a two-step purification procedure including extraction at low pH, gel filtration on Superdex 200, and ion-exchange chromatography on Mono Q. To follow the conventional nomenclature for aspartic proteinases, we have named these proteinases cardosin A and cardosin B. On SDS/PAGE, cardosin A migrated as two bands with apparent molecular masses of 31 000 Da and 15000 Da where as the chains of cardosin B migrated as bands of 34000 Da and 14000 Da. The partial amino acid sequences of the two cardosins revealed that they are similar but not identical, and that they differ horn the previously reported cardoon proteinases named cynarases, which were assumed to be derived from a common precursor. Although the cardosins show some degree of similarity to each other, we could detect no immunological cross-reactivity between them. Both cardosins were active at low pH and were inhibited by pepstatin, with Ki values of 3 nM for cardosin A and 1 nM for cardosin B, indicating that they belong to the class of aspartic proteinases. Significant differences between the two enzymes were also found for the Kcat/Km values for the hydrolysis of two chromophoric synthetic peptides. The active-site ionization constants, pKe1 and pKe2, for cardosin A are 2.5±0.2 and 5.3±20.2, whereas for cardosin R they are 3.73±10.09 and 6.7±50.1. The results herein described on the structural and kinetic properties of the cardosins indicate that they are the products of distinct genes which have probably arisen by gene duplication. A scheme for the proteolytic processing of the two enzymes is also proposed. |
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Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L.Two new aspartic proteinases have been isolated from stigmas of the cardoon Cynara cardunculus L. by a two-step purification procedure including extraction at low pH, gel filtration on Superdex 200, and ion-exchange chromatography on Mono Q. To follow the conventional nomenclature for aspartic proteinases, we have named these proteinases cardosin A and cardosin B. On SDS/PAGE, cardosin A migrated as two bands with apparent molecular masses of 31 000 Da and 15000 Da where as the chains of cardosin B migrated as bands of 34000 Da and 14000 Da. The partial amino acid sequences of the two cardosins revealed that they are similar but not identical, and that they differ horn the previously reported cardoon proteinases named cynarases, which were assumed to be derived from a common precursor. Although the cardosins show some degree of similarity to each other, we could detect no immunological cross-reactivity between them. Both cardosins were active at low pH and were inhibited by pepstatin, with Ki values of 3 nM for cardosin A and 1 nM for cardosin B, indicating that they belong to the class of aspartic proteinases. Significant differences between the two enzymes were also found for the Kcat/Km values for the hydrolysis of two chromophoric synthetic peptides. The active-site ionization constants, pKe1 and pKe2, for cardosin A are 2.5±0.2 and 5.3±20.2, whereas for cardosin R they are 3.73±10.09 and 6.7±50.1. The results herein described on the structural and kinetic properties of the cardosins indicate that they are the products of distinct genes which have probably arisen by gene duplication. A scheme for the proteolytic processing of the two enzymes is also proposed.1996info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/8139http://hdl.handle.net/10316/8139https://doi.org/10.1111/j.1432-1033.1996.00762.xengEuropean Journal of Biochemistry. 235:3 (1996) 762-768Veríssimo, PaulaFaro, CarlosMoir, Arthur J. G.Lin, YingzhangTang, JordanPires, Euclidesinfo: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:RCAAP2021-11-09T09:29:42Zoai:estudogeral.uc.pt:10316/8139Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:55:44.366114Repositório 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 |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
title |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
spellingShingle |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. Veríssimo, Paula |
title_short |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
title_full |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
title_fullStr |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
title_full_unstemmed |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
title_sort |
Purification, Characterization and Partial Amino Acid Sequencing of Two New Aspartic Proteinases from Fresh Flowers of Cynara cardunculus L. |
author |
Veríssimo, Paula |
author_facet |
Veríssimo, Paula Faro, Carlos Moir, Arthur J. G. Lin, Yingzhang Tang, Jordan Pires, Euclides |
author_role |
author |
author2 |
Faro, Carlos Moir, Arthur J. G. Lin, Yingzhang Tang, Jordan Pires, Euclides |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Veríssimo, Paula Faro, Carlos Moir, Arthur J. G. Lin, Yingzhang Tang, Jordan Pires, Euclides |
description |
Two new aspartic proteinases have been isolated from stigmas of the cardoon Cynara cardunculus L. by a two-step purification procedure including extraction at low pH, gel filtration on Superdex 200, and ion-exchange chromatography on Mono Q. To follow the conventional nomenclature for aspartic proteinases, we have named these proteinases cardosin A and cardosin B. On SDS/PAGE, cardosin A migrated as two bands with apparent molecular masses of 31 000 Da and 15000 Da where as the chains of cardosin B migrated as bands of 34000 Da and 14000 Da. The partial amino acid sequences of the two cardosins revealed that they are similar but not identical, and that they differ horn the previously reported cardoon proteinases named cynarases, which were assumed to be derived from a common precursor. Although the cardosins show some degree of similarity to each other, we could detect no immunological cross-reactivity between them. Both cardosins were active at low pH and were inhibited by pepstatin, with Ki values of 3 nM for cardosin A and 1 nM for cardosin B, indicating that they belong to the class of aspartic proteinases. Significant differences between the two enzymes were also found for the Kcat/Km values for the hydrolysis of two chromophoric synthetic peptides. The active-site ionization constants, pKe1 and pKe2, for cardosin A are 2.5±0.2 and 5.3±20.2, whereas for cardosin R they are 3.73±10.09 and 6.7±50.1. The results herein described on the structural and kinetic properties of the cardosins indicate that they are the products of distinct genes which have probably arisen by gene duplication. A scheme for the proteolytic processing of the two enzymes is also proposed. |
publishDate |
1996 |
dc.date.none.fl_str_mv |
1996 |
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/10316/8139 http://hdl.handle.net/10316/8139 https://doi.org/10.1111/j.1432-1033.1996.00762.x |
url |
http://hdl.handle.net/10316/8139 https://doi.org/10.1111/j.1432-1033.1996.00762.x |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
European Journal of Biochemistry. 235:3 (1996) 762-768 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
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 |
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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) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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