The carbohydrate-binding module of <i>Fragaria</i> × <i>ananassa</i> expansin 2 (CBM-FaExp2) binds to cell wall polysaccharides and decreases cell wall enzyme activities "in vitro"

A putative carbohydrate binding module (CBM) from strawberry (<i>Fragaria</i> × ananassa</i> Duch.) expansin 2 (CBM-FaExp2) was cloned and the encoding protein was over-expressed in <i>Escherichia coli</i> and purified in order to evaluate its capacity to bind different...

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Detalhes bibliográficos
Autores: Nardi, Cristina Fernanda, Escudero, Cristian, Villarreal, Natalia Marina, Martínez, Gustavo Adolfo, Civello, Pedro Marcos
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2013
País:Argentina
Recursos:Universidad Nacional de La Plata
Repositório:SEDICI (UNLP)
Idioma:inglês
OAI Identifier:oai:sedici.unlp.edu.ar:10915/131997
Acesso em linha:http://sedici.unlp.edu.ar/handle/10915/131997
Access Level:Acceso aberto
Palavra-chave:Ciencias Exactas
Ciencias Agrarias
CBM
Cell wall
Expansin
Hydrolases
Strawberry
Descrição
Resumo:A putative carbohydrate binding module (CBM) from strawberry (<i>Fragaria</i> × ananassa</i> Duch.) expansin 2 (CBM-FaExp2) was cloned and the encoding protein was over-expressed in <i>Escherichia coli</i> and purified in order to evaluate its capacity to bind different cell wall polysaccharides “in vitro”. The protein CBM-FaExp2 bound to microcrystalline cellulose, xylan and pectin with different affinities (K<sub>ad</sub> = 33.6 ± 0.44 mL g⁻¹, K<sub>ad</sub> = 11.37 ± 0.87 mL g⁻¹, K<sub>ad</sub> = 10.4 ± 0.19 mL g⁻¹, respectively). According to “in vitro” enzyme assays, this CBM is able to decrease the activity of cell wall degrading enzymes such as polygalacturonase, endo-glucanase, pectinase and xylanase, probably because the binding of CBM-FaExp2 to the different substrates interferes with enzyme activity. The results suggest that expansins would bind not only cellulose but also a wide range of cell wall polymers.