TY - JOUR
T1 - The catalytic cycle of nitrous oxide reductase — The enzyme that catalyzes the last step of denitrification
AU - Carreira, Cíntia
AU - Pauleta, Sofia R.
AU - Moura, Isabel
N1 - Sem PDF.
Fundacao para a Ciencia e Tecnologia (PTDC/BBB-BQB/0129/2014; SFRH/BD/87898/2012)
Unidade de Ciencias Biomoleculares Aplicadas-UCIBIO - FCT/MEC (UID/Multi/04378/2013)
ERDF (POCI-01-0145-FEDER-007728)
PY - 2017/12
Y1 - 2017/12
N2 - The reduction of the potent greenhouse gas nitrous oxide requires a catalyst to overcome the large activation energy barrier of this reaction. Its biological decomposition to the inert dinitrogen can be accomplished by denitrifiers through nitrous oxide reductase, the enzyme that catalyzes the last step of the denitrification, a pathway of the biogeochemical nitrogen cycle. Nitrous oxide reductase is a multicopper enzyme containing a mixed valence CuA center that can accept electrons from small electron shuttle proteins, triggering electron flow to the catalytic sulfide-bridged tetranuclear copper “CuZ center”. This enzyme has been isolated with its catalytic center in two forms, CuZ*(4Cu1S) and CuZ(4Cu2S), proven to be spectroscopic and structurally different. In the last decades, it has been a challenge to characterize the properties of this complex enzyme, due to the different oxidation states observed for each of its centers and the heterogeneity of its preparations. The substrate binding site in those two “CuZ center” forms and which is the active form of the enzyme is still a matter of debate. However, in the last years the application of different spectroscopies, together with theoretical calculations have been useful in answering these questions and in identifying intermediate species of the catalytic cycle. An overview of the spectroscopic, kinetics and structural properties of the two forms of the catalytic “CuZ center” is given here, together with the current knowledge on nitrous oxide reduction mechanism by nitrous oxide reductase and its intermediate species.
AB - The reduction of the potent greenhouse gas nitrous oxide requires a catalyst to overcome the large activation energy barrier of this reaction. Its biological decomposition to the inert dinitrogen can be accomplished by denitrifiers through nitrous oxide reductase, the enzyme that catalyzes the last step of the denitrification, a pathway of the biogeochemical nitrogen cycle. Nitrous oxide reductase is a multicopper enzyme containing a mixed valence CuA center that can accept electrons from small electron shuttle proteins, triggering electron flow to the catalytic sulfide-bridged tetranuclear copper “CuZ center”. This enzyme has been isolated with its catalytic center in two forms, CuZ*(4Cu1S) and CuZ(4Cu2S), proven to be spectroscopic and structurally different. In the last decades, it has been a challenge to characterize the properties of this complex enzyme, due to the different oxidation states observed for each of its centers and the heterogeneity of its preparations. The substrate binding site in those two “CuZ center” forms and which is the active form of the enzyme is still a matter of debate. However, in the last years the application of different spectroscopies, together with theoretical calculations have been useful in answering these questions and in identifying intermediate species of the catalytic cycle. An overview of the spectroscopic, kinetics and structural properties of the two forms of the catalytic “CuZ center” is given here, together with the current knowledge on nitrous oxide reduction mechanism by nitrous oxide reductase and its intermediate species.
KW - Catalytic cycle
KW - Copper enzyme
KW - CuZ
KW - Denitrification
KW - Greenhouse effect
KW - Nitrous oxide reductase
UR - http://www.scopus.com/inward/record.url?scp=85029538982&partnerID=8YFLogxK
U2 - 10.1016/j.jinorgbio.2017.09.007
DO - 10.1016/j.jinorgbio.2017.09.007
M3 - Short survey
C2 - 28927704
AN - SCOPUS:85029538982
SN - 0162-0134
VL - 177
SP - 423
EP - 434
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
ER -