Electron transferring flavoprotein
The electron-transferring flavoprotein (abbreviated ETF ) is a complex of two protein chains that is part of the respiratory chain in bacteria and eukaryotes . The heterodimer of ETF-α and ETF-β is responsible for the transport of two electrons , which are made available by FADH 2 . When people can mutations in ETFA - or ETFB - gene coding for the ETF subunits for rare inherited Glutaraciduria lead 2A (GA2A).
General
Many mitochondrial enzymes contain flavin adenine dinucleotide as a covalently linked coenzyme . While NADH is soluble and can freely diffuse to the complexes of the respiratory chain, FADH 2 is firmly bound to the respective enzyme. ETF acts here as an electron transporter. It accepts two electrons and reduces its own covalently bound FAD to FADH 2 . Finally, in turn, it surrenders the electrons to ETF ubiquinone oxidoreductase, which also contains a covalently bound FAD. This is again reduced to FADH 2 and in turn releases the electrons to the ubiquinone located in the mitochondrial inner membrane.
β-oxidation
In a crucial reaction of β-oxidation, namely the reaction of an acyl-CoA to a trans-Δ²-enoyl-CoA , catalyzed by the acyl-CoA dehydrogenase , two electrons and two protons are transferred to the FAD. These electrons reach the respiratory chain through the mechanism mentioned above.
literature
- Joachim Rassow , Karin Hauser, Roland Heutzker, Rainer Deutzmann: Biochemie , 2012, Gregor Tieme Verlag KG 2 1/2. Edition, ISBN 978-3-13-152103-3
- DL Roberts, FE Frerman, JJ Kim: Three-dimensional structure of human electron transfer flavoprotein to 2.1-A resolution. In: Proceedings of the National Academy of Sciences . Volume 93, Number 25, December 1996, pp. 14355-14360, ISSN 0027-8424 . PMID 8962055 . PMC 26136 (free full text).