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Biosíntesis de la vitamina B6 en la levadura: patrón de incorporación de la glucosa
R N Gupta1, T Hemscheidt, B G Sayer
1Department of Chemistry, McMaster University, Hamilton, Ontario, Canada L8S 4M1.
Journal of the American Chemical Society
|November 15, 2001
Resumen
El esqueleto de carbono de la vitamina B6 en la levadura se origina de manera diferente que en E. coli. La levadura utiliza un intermediario común derivado de la glucosa para la síntesis de piridoxamina y ribosa.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Microbiología Microbiología.
- Las vías metabólicas.
Sus antecedentes:
- La vitamina B6 (piridoxina y piridoxamina) es esencial para numerosos procesos metabólicos.
- Comprender la biosíntesis de la vitamina B6 en diferentes organismos es crucial para la ingeniería metabólica y las aplicaciones farmacéuticas.
- Estudios previos establecieron la vía biosintética de la vitamina B6 en Escherichia coli.
Objetivo del estudio:
- Para aclarar el origen del esqueleto de carbono de la vitamina B6 en dos especies de levadura: Saccharomyces cerevisiae y Candida utilis.
- Para comparar la vía biosintética de la vitamina B6 en la levadura con la previamente identificada en Escherichia coli.
Principales métodos:
- Incubación de Saccharomyces cerevisiae y Candida util con (13) D-glucosa etiquetada con C.
- Aislamiento y purificación del clorhidrato de piridoxamina de la levadura.
- (13)C Espectroscopia de Resonancia Magnética Nuclear ((13)C NMR) para determinar los patrones de incorporación del (13)C.
Principales resultados:
- El patrón de incorporación de (13)C en el clorhidrato de piridoxamina de levadura difería significativamente del de la piridoxina en E. coli.
- En la levadura, la cadena C ((5) de la piridoxamina mostró una distribución (13) C similar al componente ribosa de la citidina.
- Esto sugiere una pentulosa común derivada de glucosa o un intermediario de la pentosa para la síntesis de piridoxamina y ribosa en la levadura.
Conclusiones:
- La vía biosintética para el esqueleto de carbono de la vitamina B6 en la levadura es sustancialmente diferente de la de E. coli.
- Es probable que la levadura utilice un intermediario común de pentosa/pentulosa derivado de la glucosa para la síntesis de piridoxamina y ribosa.
- Este hallazgo proporciona nuevos conocimientos sobre la biosíntesis microbiana de la vitamina B6 y objetivos potenciales para la ingeniería metabólica.
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