Reaction: Salvage - BH2 is reduced to BH4 by DHFR
In the second salvage step, dihydrofolate reductase (DHFR) can regenerate BH4 from BH2, a process which increases the BH4:BH2 ratio providing BH4 for coupled eNOS production of NO. In mice cell lines, DHFR inhibition or knockdown diminishes the BH4:BH2 ratio and exacerbates eNOS uncoupling (Crabtree et al. 2009).
Reaction - small molecule participants:
BH4 [cytosol]
NADP+ [cytosol]
H+ [cytosol]
BH2 [cytosol]
NADPH [cytosol]
Reactome.org reaction link: R-HSA-1497794
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Reaction input - small molecules:
hydron
D-erythro-7,8-dihydrobiopterin
NADPH(4-)
Reaction output - small molecules:
5,6,7,8-tetrahydrobiopterin
NADP(3-)
Reactome.org link: R-HSA-1497794