FN is induced in mt-preparations by addition of NADH-generating substrates (N-pathway control state, or CI-linked pathway control) in combination with one or several fatty acids, which are supplied to feed electrons into the F-junction through fatty acyl CoA dehydrogenase (reduced form FADH2), to electron transferring flavoprotein (CETF), and further through the Q-junction to Complex III (CIII). FAO not only depends on electron transfer through the F-junction (which is typically rate-limiting), but simultaneously generates FADH2 and NADH and thus depends on N-junction throughput. Hence FAO can be inhibited completely by inhibition of Complex I (CI). This physiological substrate combination is required for partial reconstitution of TCA cycle function and convergent electron-input into the Q-junction, to compensate for metabolite depletion into the incubation medium. FS in combination exerts an additive effect of convergent electron flow in most types of mitochondria.
FN pathway in the LEAK state can be evaluated in the following SUIT protocols:
FN pathway in the OXPHOS state can be evaluated in the following SUIT protocols:
- DL-Protocol for permeabilized fibers (pfi):SUIT-005 O2 pfi D011
FN pathway in the ET state can be evaluated in the following SUIT protocols:
MitoPedia topics: EAGLE