Video Experimental Relacionado
Updated: May 17, 2026
10:43
Preparation, Purification, and Use of Fatty Acid-containing Liposomes
Published on: February 9, 2018
El cofactor de ribozima glmS es un catalizador general ácido-base
Júlia Viladoms1, Martha J Fedor
1Department of Chemical Physiology, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Journal of the American Chemical Society
|November 2, 2012
Resumen
La ribozima glmS utiliza un cofactor de d-glucosamina-6-fosfato (GlcN6P) para su producción. Este estudio muestra que GlcN6P actúa como un catalizador ácido general, participando directamente en la ribozima glmS.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- La catálisis del ARN.
Sus antecedentes:
- La ribozima glmS es un ARN autoclasificado único que requiere un cofactor.
- El papel catalítico preciso del cofactor d-glucosamina-6-fosfato (GlcN6P) aún no está claro.
- Las hipótesis anteriores sugirieron que GlcN6P funciona como un ácido general.
Objetivo del estudio:
- Para investigar el mecanismo catalítico de la ribozima glmS.
- Determinar el papel del cofactor GlcN6P en la auto-escisión de la ribozima glmS.
- Para determinar si GlcN6P actúa como un catalizador ácido general.
Principales métodos:
- Cribado de moléculas similares a GlcN6P para la actividad de autoclave de la ribozima glmS.
- Análisis de la dependencia del pH de la reacción de escisión.
- Correlación de la acidez del cofactor con la mejora de la tasa.
- Determinación del coeficiente de Brønsted (β).
Principales resultados:
- Se observó una fuerte correlación entre la dependencia del pH y la acidez del cofactor.
- La eficiencia del cofactor fue proporcional a la acidez intrínseca para los aglutinantes de baja afinidad.
- Una relación lineal de energía libre apoya un mecanismo general de catálisis ácido-base.
- Un alto coeficiente de Brønsted (β ~ 0,7) indica una transferencia significativa de protones en el estado de transición.
Conclusiones:
- El cofactor GlcN6P participa directamente en el mecanismo catalítico de la ribozima glmS.
- La ribozima glmS utiliza la catálisis ácido-base exógena, un hallazgo novedoso para los ARN de autoclave.
- Este estudio aclara el papel catalítico del cofactor GlcN6P en la función de la ribozima glmS.
Videos de Conceptos Relacionados
02:47Ribozymes
The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech’s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman’s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can be...
Ribozymes can be...
02:47Ribozymes
The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech’s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman’s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can be...
Ribozymes can be...
01:27Cofactors and Coenzymes
Enzymes require additional components for proper function. There are two such classes of molecules: cofactors and coenzymes. Cofactors are metallic ions and coenzymes are non-protein organic molecules. Both of these types of helper molecule can be tightly bound to the enzyme or bound only when the substrate binds.
01:24Cofactors and Coenzymes
Enzymes are proteins made of amino acids. The functional group of each constituent amino acid catalyzes a wide variety of chemical reactions via ionic interactions or acid-base reactions. However, amino acids cannot catalyze oxidation-reduction and group transfer reactions and need to be aided by non-protein components called cofactors. Cofactors are also referred to as the chemical teeth of an enzyme.
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
01:27Cofactors and Coenzymes
Enzymes require additional components for proper function. There are two such classes of molecules: cofactors and coenzymes. Cofactors are metallic ions and coenzymes are non-protein organic molecules. Both of these types of helper molecule can be tightly bound to the enzyme or bound only when the substrate binds.
01:13Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...