NADH electron transfer-pathway state

high-resolution terminology - matching measurements at high-resolution

NADH electron transfer-pathway state

Description

NADH-linked substrates (CI-linked) are N-junction substrates of ETS-level 4, feeding electrons into the N-junction catalyzed by various mt-dehydrogenases. N-supported flux is induced in mt-preparations by addition of NADH-generating substrate combinations of pyruvate (P), glutamate (G), malate (M), oxaloacetate (Oa), oxoglutarate (Og), citrate, hydroxybutyrate. These N-junction substrates are (indirectly) linked to Complex I by the corresponding dehydrogenase-catalyzed reactions reducing NAD⁺ to NADH+H⁺. The most commonly applied N-junction substrate combinations are: PM, GM, PGM. Malate alone is a special case related to malic enzyme (mtME). Glutamate alone supports respiration through glutamate dehydrogenase (mtGDH). In mt-preparations, succinate dehydrogenase (SDH; CII) is largely substrate-limited in N-linked respiration, due to metabolite depletion into the incubation medium. The residual involvement of S-linked respiration in the pesence of N-junction substrates can be further suppressed by the CII-inhibitor malonic acid).

Abbreviation: N

Reference: Gnaiger 2014 MitoPathways

MitoPedia concepts: MiP concept, Respiratory state, SUIT concept, SUIT state 

MitoPedia methods: Respirometry 

Contributed by Gnaiger E 2016-03-20; edited 2016-08-26, 2016-09-10.

From CI to N

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