CNS Biochemistry Flashcards
How is glutamate formed?
Transamination reaction from alpha-ketoglutarate using PLP as a cofactor. Oxidative deamination from alpha-ketoglutarate using glutamate dehydrogenase as a catalyst (requires NAD(P)H and NH3). Deamination reaction from glutamine catalyzed by glutaminase.
How is glutamine formed?
Glutamine is formed from glutamate via glutamine synthase (requires NH4+ and ATP).
How is tyrosine formed?
Tyrosine is formed from phenylalanine. Catalyzed by phenylalanine hydroxylase. Requires BH4 and O2.
How is GABA formed?
GABA is formed from a decarboxylation reaction from glutamate. Requires glutamic acid decarboxylase and PLP.
How is dopa formed?
Dopa is formed from tyrosine. Requires tyrosine hydroxylase and BH4.
How is dopamine formed?
Dopamine is formed from dopa via dopa decarboxylase and PLP.
How is norepinephrine formed?
Norepinephrine is formed from dopamine via a hydroxylation reaction. Catalyzed by dopa beta-hydroxylase. Requires O2, Cu2+, and vitamin C.
How is epinephrine formed?
Epinephrine is formed via a methylation reaction from norepinephrine. Requires SAM.
What is required to produce PLP?
Vitamin B6. B6 is inhibited by isoniazid (treatment for TB)
What is required to produce SAM?
Vitamin B12 and folate.
How is serotonin formed?
Hydroxylate and decarboxylase reactions from tryptophan. Requires BH4 and PLP.
How is histamine formed?
Histamine is formed by a decarboxylation reaction from histidine. Requires PLP.
