|Reductive nitrosylation of Methanosarcina acetivorans protoglobin: a comparative study|Ascenzi, P.; Pesce, A.; Nardini, M.; Bolognesi, M.; Ciaccio, C.; Coletta, M.; Dewilde, S. (2013). Reductive nitrosylation of Methanosarcina acetivorans protoglobin: a comparative study. Biochem. Biophys. Res. Commun. 430(4): 1301-1305. dx.doi.org/10.1016/j.bbrc.2012.11.122
In: Biochemical and Biophysical Research Communications. ACADEMIC PRESS INC ELSEVIER SCIENCE: San Diego etc.. ISSN 0006-291X, more
Methanosarcina acetivorans protoglobin; Reductive nitrosylation offerric; Methanosarcina acetivorans protoglobin; Nitrosylation of ferrousMethanosarcina acetivorans protoglobin; Kinetics; Thermodynamics
|Authors|| || Top |
- Ascenzi, P.
- Pesce, A.
- Nardini, M.
- Bolognesi, M.
- Ciaccio, C.
- Coletta, M.
- Dewilde, S., more
Methanosarcina acetivorans is a strictly anaerobic non-motile methane-producing Archaea expressing protoglobin (Pgb) which might either facilitate O2 detoxification or act as a CO sensor/supplier in methanogenesis. Unusually, M. acetivorans Pgb (MaPgb) binds preferentially O2 rather than CO and displays anticooperativity in ligand binding. Here, kinetics and/or thermodynamics of ferric and ferrous MaPgb (MaPgb(III) and MaPgb(II), respectively) nitrosylation are reported. Data were obtained between pH 7.2 and 9.5, at 22.0 °C. Addition of NO to MaPgb(III) leads to the transient formation of MaPgb(III)–NO in equilibrium with MaPgb(II)–NO+. In turn, MaPgb(II)–NO+ is converted to MaPgb(II) by OH−-based catalysis. Then, MaPgb(II) binds NO very rapidly leading to MaPgb(II)–NO. The rate-limiting step for reductive nitrosylation of MaPgb(III) is represented by the OH−-mediated reduction of MaPgb(II)–NO+ to MaPgb(II). Present results highlight the potential role of MaPgb in scavenging of reactive nitrogen and oxygen species.