Video Experimental Relacionado
Updated: Jul 7, 2026
08:57
Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
Published on: February 24, 2018
La reductasa de óxido nitroso reductivamente activada reacciona directamente con el sustrato
Jeannine M Chan1, John A Bollinger, Cassidy L Grewell
1Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
Journal of the American Chemical Society
|March 12, 2004
Resumen
La óxido nitroso reductasa convierte N2O en N2 en su centro CuZ. Este estudio muestra que la enzima activada se une a N2O, revelando un potencial estado intermedio catalítico.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Microbiología Microbiología.
- Enzimología Enzimología.
Sus antecedentes:
- La desnitrificación bacteriana convierte los óxidos de nitrógeno, con la reductasa de óxido nitroso (N2OR) catalizando la conversión final de N2O a N2.
- El sitio activo de la enzima, el centro CuZ tetranuclear con puente de mu4-sulfuro, es crucial para esta reacción.
Objetivo del estudio:
- Para investigar la interacción con el sustrato y el mecanismo catalítico de N2OR de los cicloclastos de Achromobacter.
- Para caracterizar el estado de oxidación del centro CuZ en la enzima activada.
Principales métodos:
- Aislamiento y caracterización del N2OR activado reductivamente.
- Absorción visible y espectroscopia de resonancia paramagnética de electrones (EPR).
- Los ensayos enzimáticos con N2O. etiquetado con 15N.
Principales resultados:
- La activación reductora por metilviologen aumentó la actividad específica N2OR hasta 15 veces.
- El análisis espectroscópico confirmó que el centro CuZ puede alcanzar un estado de oxidación [4Cu(I).
- Los cambios espectrales tras la adición de N2O y la detección del producto etiquetado indicaron una interacción con el sustrato y un potencial intermediario catalítico.
Conclusiones:
- El N2OR activado se une al N2O, lo que sugiere un paso de interacción del sustrato antes de la rotación en estado estacionario.
- Una nueva banda de absorción a 970 nm puede significar un intermediario catalítico clave en la reducción de N2O.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:24Redox Reactions
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
02:34Enzymes
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
01:30The Electron Transport Chain
The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is coupled to ATP synthesis. This process is a significant source of energy in aerobic cells, and therefore inhibitors of the electron transport chain can be detrimental to the cell's metabolic processes.
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
01:19Oxidation and Reduction of Organic Molecules
Energy production within a cell involves many coordinated chemical pathways. Most of these pathways are combinations of oxidation and reduction reactions, which occur at the same time. An oxidation reaction strips an electron from an atom in a compound, and the addition of this electron to another compound is a reduction reaction. Because oxidation and reduction usually occur together, these pairs of reactions are called redox reactions.
The removal of an electron from a molecule, results in a...
The removal of an electron from a molecule, results in a...
01:22Factors Influencing the Rate of Chemical Reactions
A variety of factors influence the rate of chemical reactions. For a chemical reaction to happen, atoms must collide with enough energy to overcome the repulsion between their electrons. This energy is called activation energy. Factors influencing the rate of reaction either lower the activation energy or increase the likelihood of a successful collision.
Concentration and Pressure:
The more particles present within a given space, the more likely those particles are to bump into one another.
Concentration and Pressure:
The more particles present within a given space, the more likely those particles are to bump into one another.
01:27Redox Reactions
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...