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Provedor de dados:  BABT
País:  Brazil
Título:  Production of D-myo-inositol(1,2,4,5,6)pentakisphosphate using alginate-entrapped recombinant Pantoea agglomerans glucose-1-phosphatase
Autores:  Greiner,Ralf
Sajidan,
Data:  2008-04-01
Ano:  2008
Palavras-chave:  Entrapment
Glucose-1-phosphatase
Myo-inositol pentakisphosphate Pantoea agglomerans
Phytase
Resumo:  The glucose-1-phosphatase encoding gene (agp) of Pantoea agglomerans was sequenced and heterologously expressed in Escherichia coli. The enzyme showed very high homology to periplasmatic glucose-1-phosphatases of other members of the Enterobacteriaceae family. It was isolated from transformed Escherichia coli cells in a single step in high yields (32.3 ± 1.2 mg per litre of culture) by Ni-NT agarose affinity chromatography to >95% purity as calculated from specific activity determinations. The purified glucose-1-phosphatase was entrapped in alginate beads with an entrapment efficiency of >80%. Temperature stability was enhanced as a consequence of entrapment, whereas pH dependence of enzyme activity was not affected. Maximum catalytic activity of entrapped glucose-1-phosphatase was found at 70°C, whereas the free enzyme exhibited maximal activity at 60°C. A single pH optimum at pH 4.5 was determined for the free and the entrapped enzyme. Kinetic parameters for the hydrolysis of sodium phytate were found to be affected by entrapment. They were determined to be K M = 0.84 mmol l-1 and k cat = 8 s-1 at pH 4.5 and 37°C for the entrapped glucose-1-phosphatase and K M = 0.35 mmol l-1 and k cat = 20.5 s-1 for the free enzyme. Complete conversion of phytate into one single myo-inositol pentakisphosphate isomer, identified as D-myo-inositol(1,2,4,5,6)pentakis-phosphate, was shown to be feasible by using the enzyme-loaded alginate beads in batch operations. The entrapped enzyme showed a high operational stability by retaining almost full activity even after ten uses.
Tipo:  Info:eu-repo/semantics/article
Idioma:  Inglês
Identificador:  http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000200002
Editor:  Instituto de Tecnologia do Paraná - Tecpar
Relação:  10.1590/S1516-89132008000200002
Formato:  text/html
Fonte:  Brazilian Archives of Biology and Technology v.51 n.2 2008
Direitos:  info:eu-repo/semantics/openAccess
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