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https://hdl.handle.net/1822/22280
Título: | Conversion of β-carotene into astaxanthin : two separate enzymes or a bifunctional hydroxylase-ketolase protein? |
Autor(es): | Martín, Juan F. Gudiña, Eduardo J. Barredo, José L. |
Data: | 2008 |
Editora: | BioMed Central (BMC) |
Revista: | Microbial Cell Factories |
Resumo(s): | Astaxanthin is a xanthophyll of great interest in animal nutrition and human health. The market prospect in the nutraceutics industries for this health-protective molecule is very promising. Astaxanthin is synthesized by several bacteria, algae and plants from β-carotene by the sequential action of two enzymes: a β-carotene, 3,3'-hydroxylase that introduces an hydroxyl group at the 3 (and 3') positions of each of the two β-ionone rings of β-carotene, and a β-carotene ketolase that introduces keto groups at carbons 4 and 4' of the β-ionone rings. Astaxanthin is also produced by the yeast-like basidiomycete Xanthophyllomyces dendrorhous. A gene crtS involved in the conversion of β-carotene to astaxanthin has been cloned simultaneously by two research groups. Complementation studies of X. dendrorhous mutants and expression analysis in Mucor circinelloides reveals that the CrtS enzyme is a β-carotene hydroxylase of the P-450 monooxygenase family that converts β-carotene to the hydroxylated derivatives β-cryptoxanthin and zeaxanthin, but it does not form astaxanthin or the ketolated intermediates in this fungus. A bifunctional β-carotene hydroxylase-ketolase activity has been proposed for the CrtS protein. The evidence for and against this hypothesis is analyzed in detail in this review. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/22280 |
DOI: | 10.1186/1475-2859-7-3 |
ISSN: | 1475-2859 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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1475-2859-7-3.pdf | 558,9 kB | Adobe PDF | Ver/Abrir |