Alternative Routes for the Synthesis of 5-Aminolevulinic Acid in Maize Leaves
نویسندگان
چکیده
منابع مشابه
Alternative Routes for the Synthesis of 5-Aminolevulinic Acid in Maize Leaves : II. Formation from Glutamate.
Intact plastids from greening maize (Zea mays L.) leaves converted [(14)C]glutamate and [(14)C]2-ketoglutarate (KG) to [(14)C]5-aminolevulinic acid (ALA). Glutamate appeared to be the immediate precursor of ALA, while KG was first converted to glutamate, as shown by the effect of various inhibitors of amino acid metabolism. Plastids from greening leaves contained markedly higher activity as com...
متن کاملAlternative Routes for the Synthesis of 5-Aminolevulinic Acid in Maize Leaves : I. Formation from 2-Ketoglutarate via 4,5-Dioxovaleric Acid.
Cell-free extracts from greening maize (Zea mays L.) leaves catalyze the conversion of [(14)C]2-ketoglutarate (KG) to [(14)C]5-aminolevulinic acid (ALA) in a reaction which requires NADH and an amino donor and shows maximal activity around pH 6.5. The enzymic system is located in the cytosol. This cell fraction contains a low level of ;KG dehydrogenase' activity and a transaminase which catalyz...
متن کامل5-Aminolevulinic acid synthesis in Escherichia coli.
A hemA mutant of Escherichia coli containing a multicopy plasmid which complemented the mutation excreted 5-aminolevulinic acid (ALA) into the medium. [1-14C]glutamate was substantially incorporated into ALA by this strain, whereas [2-14C]glycine was not. Periodate degradation of labeled ALA showed that C-5 of ALA was derived from C-1 of glutamate. The synthesis of ALA by two sonicate fractions...
متن کاملRapid dark repression of 5-aminolevulinic acid synthesis in green barley leaves.
In photosynthetic organisms chlorophyll and heme biosynthesis is tightly regulated at various levels in response to environmental adaptation and plant development. The formation of 5-aminolevulinic acid (ALA) is the key regulatory step and provides adequate amounts of the common precursor molecule for the Mg and Fe branches of tetrapyrrole biosynthesis. Pathway control prevents accumulation of ...
متن کاملAlternative kynurenic acid synthesis routes studied in the rat cerebellum
Kynurenic acid (KYNA), an astrocyte-derived, endogenous antagonist of α7 nicotinic acetylcholine and excitatory amino acid receptors, regulates glutamatergic, GABAergic, cholinergic and dopaminergic neurotransmission in several regions of the rodent brain. Synthesis of KYNA in the brain and elsewhere is generally attributed to the enzymatic conversion of L-kynurenine (L-KYN) by kynurenine amino...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Plant Physiology
سال: 1983
ISSN: 0032-0889,1532-2548
DOI: 10.1104/pp.72.4.1062