Oversized ubiquinones as molecular probes for structural dynamics of the ubiquinone reaction site in mitochondrial respiratory complex I was written by Uno, Shinpei;Masuya, Takahiro;Shinzawa-Itoh, Kyoko;Lasham, Jonathan;Haapanen, Outi;Shiba, Tomoo;Inaoka, Daniel Ken;Sharma, Vivek;Murai, Masatoshi;Miyoshi, Hideto. And the article was included in Journal of Biological Chemistry in 2020.Computed Properties of C9H10O4 This article mentions the following:
NADH-quinone oxidoreductase (complex I) couples electron transfer from NADH to quinone with proton translocation across the membrane. Quinone reduction is a key step for energy transmission from the site of quinone reduction to the remotely located proton-pumping machinery of the enzyme. Although structural biol. studies have proposed the existence of a long and narrow quinone-access channel, the physiol. relevance of this channel remains debatable. We investigated here whether complex I in bovine heart submitochondrial particles (SMPs) can catalytically reduce a series of oversized ubiquinones (OS-UQs), which are highly unlikely to transit the narrow channel because their side chain includes a bulky “block” that is ∼13 Å across. We found that some OS-UQs function as efficient electron acceptors from complex I, accepting electrons with an efficiency comparable with ubiquinone-2. The catalytic reduction and proton translocation coupled with this reduction were completely inhibited by different quinone-site inhibitors, indicating that the reduction of OS-UQs takes place at the physiol. reaction site for ubiquinone. Notably, the proton-translocating efficiencies of OS-UQs significantly varied depending on their side-chain structures, suggesting that the reaction characteristics of OS-UQs affect the predicted structural changes of the quinone reaction site required for triggering proton translocation. These results are difficult to reconcile with the current channel model; rather, the access path for ubiquinone may be open to allow OS-UQs to access the reaction site. Nevertheless, contrary to the observations in SMPs, OSUQs were not catalytically reduced by isolated complex I reconstituted into liposomes. We discuss possible reasons for these contradictory results. In the experiment, the researchers used many compounds, for example, 2,3-Dimethoxy-5-methylcyclohexa-2,5-diene-1,4-dione (cas: 605-94-7Computed Properties of C9H10O4).
2,3-Dimethoxy-5-methylcyclohexa-2,5-diene-1,4-dione (cas: 605-94-7) belongs to ethers. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil. Ethyl ether is an excellent solvent for extractions and for a wide variety of chemical reactions. It is also used as a volatile starting fluid for diesel engines and gasoline engines in cold weather. Dimethyl ether is used as a spray propellant and refrigerant. Methyl t-butyl ether (MTBE) is a gasoline additive that boosts the octane number and reduces the amount of nitrogen-oxide pollutants in the exhaust. The ethers of ethylene glycol are used as solvents and plasticizers.Computed Properties of C9H10O4
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem