Unravelling the carbohydrate specificity of MelA from Lactobacillus plantarum WCFS1: An α-galactosidase displaying regioselective transgalactosylation
This comprehensive work addresses, for the first time, the heterologous production, purification, biochemical characterization and carbohydrate specificity of MelA, a cold-active α-galactosidase belonging to the Glycoside Hydrolase family 36, from the probiotic organism Lactobacillus plantarum WCFS1...
| Autores: | , , , , , , |
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| Formato: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2020 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/203889 |
| Acesso em linha: | http://hdl.handle.net/10261/203889 |
| Access Level: | acceso abierto |
| Palavra-chave: | α-Galactosidase Lactobacillus plantarum WCFS1 Prebiotics |
| Resumo: | This comprehensive work addresses, for the first time, the heterologous production, purification, biochemical characterization and carbohydrate specificity of MelA, a cold-active α-galactosidase belonging to the Glycoside Hydrolase family 36, from the probiotic organism Lactobacillus plantarum WCFS1. The hydrolytic activity of MelA α-galactosidase on a wide range of p-nitrophenyl glycoside derivatives and carbohydrates of different molecular-weights showed its high selectivity and efficiency towards the α(1 → 6) glycosidic bonds involving the anomeric carbon of galactose and the C6-hydroxyl group of galactose or glucose units. MelA α-galactosidase also presented a high regioselectivity, efficiency and diversity in accommodating donor and acceptor substrates for the synthesis of α-GOS through transgalactosylation reactions. The catalytic mechanism of MelA for the production of α-GOS was elucidated, revealing its great preference for the transfer of galactosyl residues to the C6-hydroxyl group of galactose units to elongate the chain of α-GOS having either a terminal sucrose (raffinose family oligosaccharides, RFOS) or a terminal glucose (melibiose, manninotriose and verbascotetraose). Our findings indicate the feasibility of using MelA α-galactosidase from Lactobacillus plantarum WCFS1 in the hydrolysis of RFOS and in the efficient and versatile synthesis of α-GOS with appealing functional properties in the context of food and nutraceutical applications. |
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