The multicopper oxidase from the hyperthermophilic archaeon Pyrobaculum aerophilum McoP was produced in Escherichia coli and purified to homogeneity. The enzyme consists of a single subunit with 49.6-kDa and the combined results of UV-visible, CD, EPR and resonance Raman showed the typical spectroscopic characteristics of the multicopper oxidases. Analysis of the McoP sequence allowed its structure to be derived by comparative modeling methods. McoP is a hyperthermoactive and thermostable enzyme with an optimum reaction temperature of 85°C, a half-life of inactivation of around 6 h at 80°C, and temperature values at the mid point from 97 to 112°C. McoP is an efficient metallo-oxidase that catalyzes the oxidation of cuprous and ferrous ions with turnover rates of 356 and 128 min-1, respectively, at 40°C. Is is noteworthy that McoP follows a ping-pong mechanism with 3-fold higher catalytic efficiency when using nitrous oxide as electron acceptor than when using dioxygen, the typical oxidizing substrate of multicopper oxidases. This finding led us to propose that McoP represents a novel archaeal nitrous oxide reductase most probably involved in the final step of the denitrification pathway of P. aerophilum.

FERNANDES A., T., DAMAS J., M., Todorovic, S., Huber, R., Baratto, M.C., Pogni, R., et al. (2010). The multicopper oxidase from the archeon Pyrobaculum aerophilum shows nitrous oxide reductase activity. THE FEBS JOURNAL, 277, 3176-3189 [10.1111/j.1742-4658.2010.07725.x].

The multicopper oxidase from the archeon Pyrobaculum aerophilum shows nitrous oxide reductase activity

BARATTO, MARIA CAMILLA;POGNI, REBECCA;
2010

Abstract

The multicopper oxidase from the hyperthermophilic archaeon Pyrobaculum aerophilum McoP was produced in Escherichia coli and purified to homogeneity. The enzyme consists of a single subunit with 49.6-kDa and the combined results of UV-visible, CD, EPR and resonance Raman showed the typical spectroscopic characteristics of the multicopper oxidases. Analysis of the McoP sequence allowed its structure to be derived by comparative modeling methods. McoP is a hyperthermoactive and thermostable enzyme with an optimum reaction temperature of 85°C, a half-life of inactivation of around 6 h at 80°C, and temperature values at the mid point from 97 to 112°C. McoP is an efficient metallo-oxidase that catalyzes the oxidation of cuprous and ferrous ions with turnover rates of 356 and 128 min-1, respectively, at 40°C. Is is noteworthy that McoP follows a ping-pong mechanism with 3-fold higher catalytic efficiency when using nitrous oxide as electron acceptor than when using dioxygen, the typical oxidizing substrate of multicopper oxidases. This finding led us to propose that McoP represents a novel archaeal nitrous oxide reductase most probably involved in the final step of the denitrification pathway of P. aerophilum.
File in questo prodotto:
File Dimensione Formato  
FEBS_2010.pdf

non disponibili

Tipologia: Post-print
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 1.5 MB
Formato Adobe PDF
1.5 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/22299
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo