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Los impulsores evolutivos de la termoadaptación en la catálisis enzimática
Vy Nguyen1, Christopher Wilson1, Marc Hoemberger1
1Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA 02452, USA.
Science (New York, N.Y.)
|December 24, 2016
Resumen
Las enzimas evolucionaron para mantener la velocidad catalítica en temperaturas más frías utilizando la capacidad de calor del estado de transición. Este estudio revela los mecanismos moleculares de la termoadaptación en la adenilato quinasa a través de 3 mil millones de años de evolución.
Área de la Ciencia:
- La bioquímica
- Biología evolutiva
- Biología molecular
Sus antecedentes:
- La vida temprana evolucionó en ambientes calientes, lo que plantea desafíos para la función de las enzimas a medida que disminuían las temperaturas.
- Las enzimas necesitan mantener la eficiencia catalítica a pesar de las fluctuaciones de temperatura.
Objetivo del estudio:
- Investigar los mecanismos moleculares de la termoadaptación en la catálisis de la adenilatocinasa.
- Para entender cómo las enzimas evolucionaron para funcionar a través de una amplia gama de temperaturas durante más de 3 mil millones de años.
Principales métodos:
- Reconstrucción de la secuencia ancestral de adenilato quinasa que abarca 3 mil millones de años.
- Caracterización de la actividad enzimática y la estabilidad en escalas de tiempo evolutivas.
- Análisis de los mecanismos moleculares subyacentes a la velocidad catalítica y a la termoadaptación.
Principales resultados:
- La adaptación evolutiva de la adenilatocinasa a temperaturas más bajas se logró mediante la explotación de la capacidad térmica del estado de transición.
- El rastreo de la evolución enzimática reveló presiones evolutivas activas y refutó la compensación actividad/estabilidad.
- La velocidad catalítica de la adenilatocinasa se identificó como un impulsor evolutivo para la aptitud del organismo.
Conclusiones:
- La termoadaptación enzimática es impulsada por la explotación de propiedades termodinámicas como la capacidad térmica de estado de transición.
- La historia evolutiva de las enzimas proporciona información sobre la adaptación molecular y la aptitud del organismo.
- La velocidad catalítica de la adenilatocinasa es un factor clave en su éxito evolutivo.
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