Exploring the quinone/inhibitor-binding pocket in mitochondrial respiratory complex I by chemical biology approaches was written by Uno, Shinpei;Kimura, Hironori;Murai, Masatoshi;Miyoshi, Hideto. And the article was included in Journal of Biological Chemistry in 2019.COA of Formula: C9H10O4 This article mentions the following:
NADH-quinone oxidoreductase (respiratory complex I) couples NADH-to-quinone electron transfer to the translocation of protons across the membrane. Even though the architecture of the quinone-access channel in the enzyme has been modeled by X-ray crystallog. and cryo-EM, conflicting findings raise the question whether the models fully reflect physiol. relevant states present throughout the catalytic cycle. To gain further insights into the structural features of the binding pocket for quinone/inhibitor, we performed chem. biol. experiments using bovine heart sub-mitochondrial particles. We synthesized ubiquinones (UQs) that are oversized ,(i.e., SF-UQs) or lipid-like (i.e., PC-UQs) and are highly unlikely to enter and transit the predicted narrow channel. We found that SF-UQs and PC-UQs can be catalytically reduced by complex I, albeit only at moderate or low rates. Moreover, quinone-site inhibitors completely blocked the catalytic reduction and the membrane potential formation coupled to this reduction Photoaffinity-labeling experiments revealed that amiloride-type inhibitors bind to the interfacial domain of multiple core subunits (49 kDa, ND1, and PSST) and the 39-kDa supernumerary subunit, although the latter does not make up the channel cavity in the current models. The binding of amilorides to the multiple target subunits was remarkably suppressed by other quinone-site inhibitors and SF-UQs. Taken together, the present results are difficult to reconcile with the current channel models. On the basis of comprehensive interpretations of the present results and of previous findings, we discuss the physiol. relevance of these models. In the experiment, the researchers used many compounds, for example, 2,3-Dimethoxy-5-methylcyclohexa-2,5-diene-1,4-dione (cas: 605-94-7COA of Formula: C9H10O4).
2,3-Dimethoxy-5-methylcyclohexa-2,5-diene-1,4-dione (cas: 605-94-7) belongs to ethers. The oxygen atom in ethers are more electronegative than carbon, thus the hydrogens which are alpha to the ethers are more acidic than the simple hydrocarbons. The unique properties of ethers (i.e., that they are strongly polar, with nonbonding electron pairs but no hydroxyl group) enhance the formation and use of many reagents. For example, Grignard reagents cannot form unless an ether is present to share its lone pair of electrons with the magnesium atom. Complexation of the magnesium atom stabilizes the Grignard reagent and helps to keep it in solution.COA of Formula: C9H10O4
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem