Cytochrome mechanism involved

Mechanism of Cytochrome P450 Involvement in Drug Interactions... 

The binding of small inorganic ions such as [Fe(CN)6]3 and [Cr(en)3]3+ can be used to explore binding sites on electron-transfer proteins. Thus redox inactive [Cr(en)3]3+ inhibits the oxidation of cytochrome bs with [Co(NH3)6]3+ and other oxidizing agents, and also blocks association with cytochrome c. The reaction of cytochrome b5 with the oxidants occurs by a mechanism involving association of the reactants prior to electron transfer. The reaction may then be inhibited by redox... 

As molecules increase in complexity, the number of possibilities for mechanism of action also increase. For example, Structure 17.10 inhibits a specific kinase and specific cellular second messenger.111 In contrast, Structure 17.11 is specifically related to vitamin B2,112 while Structure 17.12, a steroid peroxide,113 is, in the imagination of this author, a molecule likely to impact steroid receptors and enzymes like cytochrome p450s involved in steroid metabolism. However, it is likely that the multiple functions observed for many complex natural products are a result of their interaction with multiple pathways and mechanisms. The environmental fates and... 

The second proton transfer mechanism involves protonation of carboxyl or histidyl groups associated with electron carriers in the membrane and release of protons from these sites through proposed channels when the electron carrier is oxidized. This is essentially a proton channel system with movement through the channel gated by the oxidation-reduction state of the prosthetic group on the electron transport protein. The classical example of this is seen in cytochrome c oxidase (Figure 3). 

As with cytochrome P-450 oxidations of alkanes, the mechanism of P-450-catalyzed formation of oxiranes has been extensively studied, but certain details remain in dispute272. Examples of mechanistic schemes include formation of a transient [FeIV—0]+2-olefin complex followed by collapse to an [Fe—Oj-olefin adduct that collapses further to the epoxide and other products264. An alternative mechanism involves a 2a + 2s addition of olefin to the Fe=0 double bond to give an intermediate metallocene, followed by rearrangement to products273-275. 

Figure 5. Possible mechanism for reduction of 02 in cytochrome oxidase involving the binuclear heme-copper site. (Reproduced from reference 10. Copyright 1990 American Chemical Society.)...

---