The genome-encoded quinol-cytochrome- c oxidoreductase (bc 1, Complex III homologue) potentially links oxidation of quinols to the generation of a proton membrane gradient and the reduction of terminal electron acceptors, discussed next.
Overproduction of ROIs can readily cause oxidative damage to various biological macromolecules resulting in DNA damage, oxidation of key amino acid side chains, formation of protein-protein cross-links, oxidation of the polypeptide backbone resulting in protein fragmentation, and lipid peroxidation.
In the course of oxidative phosphorylation, molecules of NADH and FADH2 are subjected to a series of linked oxidation-reduction reactions.
Together these data suggest BiP modification may account for the observed translocation attenuation; however, at present we are unable to definitively link BiP oxidation with a block in polypeptide translocation.
In this paragraph, we summarize recent data in which a link between oxidation, alterations of T-cell function and renal disease has been proposed and we also discuss potential therapeutic implications (see Table 1).
We agree that further experimental evidence for the imposition of a translocation defect by modified BiP is necessary to provide a more compelling link between oxidation of BiP and translocation attenuation.
Unlike all the other γ-proteobacteria containing HupSL, the hup operon in the S. velum symbiont does not encode the di-heme cytochrome b, which is necessary to link H2 oxidation to quinone reduction in the cellular membrane [ 56].
Interestingly, emerging evidence provides a close link between oxidation and inflammation, since excessive or uncontrolled free radical production can induce an inflammatory response and free radicals are inflammation effectors [ 69].
The yellowing of mechanically recycled PET is also a significant problem because of the intramolecular cross-linking and oxidation reactions (Edge et al. 1996).
The TCA cycle links the oxidation of pyruvate and malate with the generation of NADH.
