A broad pH range and processive chitinase from a metagenome library
Chitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4) present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Divulgação Científica
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| Series: | Brazilian Journal of Medical and Biological Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017000100602&lng=en&tlng=en |
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| author | S.S. Thimoteo A. Glogauer H. Faoro E.M. de Souza L.F. Huergo B.M. Moerschbacher F.O. Pedrosa |
| author_facet | S.S. Thimoteo A. Glogauer H. Faoro E.M. de Souza L.F. Huergo B.M. Moerschbacher F.O. Pedrosa |
| author_sort | S.S. Thimoteo |
| collection | DOAJ |
| description | Chitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4) present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading to the isolation and identification of a chitinase gene named metachi18A. The metachi18A gene was subcloned and overexpressed in Escherichia coli BL21 and the MetaChi18A chitinase was purified by affinity chromatography as a 6xHis-tagged fusion protein. The MetaChi18A enzyme is a 92-kDa protein with a conserved active site domain of glycosyl hydrolases family 18. It hydrolyses colloidal chitin with an optimum pH of 5 and temperature of 50°C. Moreover, the enzyme retained at least 80% of its activity in the pH range from 4 to 9 and 98% at 600 mM NaCl. Thin layer chromatography analyses identified chitobiose as the main product of MetaChi18A on chitin polymers as substrate. Kinetic analysis showed inhibition of MetaChi18A activity at high concentrations of colloidal chitin and 4-methylumbelliferyl N,N′-diacetylchitobiose and sigmoid kinetics at low concentrations of colloidal chitin, indicating a possible conformational change to lead the chitin chain from the chitin-binding to the catalytic domain. The observed stability and activity of MetaChi18A over a wide range of conditions suggest that this chitinase, now characterized, may be suitable for application in the industrial processing of chitin. |
| first_indexed | 2024-12-20T12:32:17Z |
| format | Article |
| id | doaj.art-3002a1b1584a46889dff3646e7f86891 |
| institution | Directory Open Access Journal |
| issn | 1414-431X |
| language | English |
| last_indexed | 2024-12-20T12:32:17Z |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-3002a1b1584a46889dff3646e7f868912022-12-21T19:40:41ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research1414-431X50110.1590/1414-431x20165658S0100-879X2017000100602A broad pH range and processive chitinase from a metagenome libraryS.S. ThimoteoA. GlogauerH. FaoroE.M. de SouzaL.F. HuergoB.M. MoerschbacherF.O. PedrosaChitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4) present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading to the isolation and identification of a chitinase gene named metachi18A. The metachi18A gene was subcloned and overexpressed in Escherichia coli BL21 and the MetaChi18A chitinase was purified by affinity chromatography as a 6xHis-tagged fusion protein. The MetaChi18A enzyme is a 92-kDa protein with a conserved active site domain of glycosyl hydrolases family 18. It hydrolyses colloidal chitin with an optimum pH of 5 and temperature of 50°C. Moreover, the enzyme retained at least 80% of its activity in the pH range from 4 to 9 and 98% at 600 mM NaCl. Thin layer chromatography analyses identified chitobiose as the main product of MetaChi18A on chitin polymers as substrate. Kinetic analysis showed inhibition of MetaChi18A activity at high concentrations of colloidal chitin and 4-methylumbelliferyl N,N′-diacetylchitobiose and sigmoid kinetics at low concentrations of colloidal chitin, indicating a possible conformational change to lead the chitin chain from the chitin-binding to the catalytic domain. The observed stability and activity of MetaChi18A over a wide range of conditions suggest that this chitinase, now characterized, may be suitable for application in the industrial processing of chitin.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017000100602&lng=en&tlng=enChitinaseMetagenomicAeromonasKinetics |
| spellingShingle | S.S. Thimoteo A. Glogauer H. Faoro E.M. de Souza L.F. Huergo B.M. Moerschbacher F.O. Pedrosa A broad pH range and processive chitinase from a metagenome library Brazilian Journal of Medical and Biological Research Chitinase Metagenomic Aeromonas Kinetics |
| title | A broad pH range and processive chitinase from a metagenome library |
| title_full | A broad pH range and processive chitinase from a metagenome library |
| title_fullStr | A broad pH range and processive chitinase from a metagenome library |
| title_full_unstemmed | A broad pH range and processive chitinase from a metagenome library |
| title_short | A broad pH range and processive chitinase from a metagenome library |
| title_sort | broad ph range and processive chitinase from a metagenome library |
| topic | Chitinase Metagenomic Aeromonas Kinetics |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017000100602&lng=en&tlng=en |
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