The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle

Stable Identifier
R-HSA-1497784
Type
Reaction [binding]
Species
Homo sapiens
Compartment
cytosol, plasma membrane
ReviewStatus
5/5
Locations in the PathwayBrowser
Expand all
General
SVG | 
PNG
Low
Medium
High
 | PPTX  | SBGN
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout
The cofactor tetrahydrobiopterin (BH4) ensures endothelial nitric oxide synthase (eNOS) couples electron transfer to L-arginine oxidation (Berka et al. 2004). During catalysis, electrons derived from NADPH transfer to the flavins FAD and FMN in the reductase domain of eNOS and then on to the ferric heme in the oxygenase domain of eNOS. BH4 can donate an electron to intermediates in this electron transfer and is oxidised in the process, forming the BH3 radical. This radical can be reduced back to BH4 by iron, completing the cycle and forming ferrous iron again. Heme reduction enables O2 binding and L-arginine oxidation to occur within the oxygenase domain (Stuehr et al. 2009).
Literature References
PubMed ID Title Journal Year
15476407 Redox function of tetrahydrobiopterin and effect of L-arginine on oxygen binding in endothelial nitric oxide synthase

Berka, V, Yeh, HC, Tsai, AL, Kiran, F, Gao, D

Biochemistry 2004
Participants
Input
Output
Participates
as an event of
Orthologous Events
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Bos taurus)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Caenorhabditis elegans)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Dictyostelium discoideum)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Drosophila melanogaster)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Gallus gallus)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Mus musculus)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Plasmodium falciparum)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Rattus norvegicus)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Saccharomyces cerevisiae)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Schizosaccharomyces pombe)
The cofactor BH4 is required for electron transfer in the eNOS catalytic cycle (Sus scrofa)
Authored
Jassal, B  (2011-08-17)
Reviewed
D'Eustachio, P  (2011-08-23)
Created
Jassal, B  (2011-08-17)
Cite Us!