Iron sulfur containing

Krasotkina J, T Walters, KA Maruya, SW Ragsdale (2001) Characterization of the Bjj- and iron-sulfur-containing reductive dehalogenase from Desulfitobacterium chlororespirans. J Biol Chem 276 40991-40997. 

It is noteworthy that except for the Rieske center in Complex III, Complexes I and 11 are home to all the iron-sulfur clusters in the mitochondrial electron transfer chain and consequently most of the iron-containing carriers in the entire sequence. Hibbs subsequently showed that CAM-injured cells lose a substantial portion of their total intracellular iron (Hibbs et al., 1984) [later studies specifically identified loss of mitochondrial iron (Wharton et al., 1988)] and Drapier and Hibbs (1986) showed that the activity of another iron-sulfur-containing enzyme, aconitase, is also lost. In early 1987 Hibbs reported that the cytostatic actions of CAMs requires the presence of only one component in culture medium, L-arginine (Hibbs et al., 1987b). Thus, the stage was set for the discovery of a unique reactive species that targets intracellular iron, produced by CAMs. 

In their paper in 1987, Hibbs et al. (1987a) proposed that the characteristic pattern of metabolic dysfunction inflicted by CAMs is due to iron loss from aconitase and other iron-sulfur-containing enzymes resulting from nitrite or oxygenated nitrogen intermediates in the pathway of nitrite and nitrate synthesis. Much data have since been published to support this proposal, although as described below the chemical details of this process are still not clear. 

As early as 1976 it was demonstrated that NO treatment of iron-sulfur-containing enzymes of the mitochondrial electron transfer chain results in liberation of iron from the clusters (Salerno et al., 1976). Hibbs et al. (1988) and Stuehr and Nathan (1989) demonstrated that treatment of tumor target cells with NO... 

Hyman, M. R., and Arp, D. J. (1991). Kinetic analysis of the interaction of nitric oxide with the membrane-associated, nickel and iron-sulfur-containing hydrogenase from Azotobacter vinelandii. Biochim. Biophys. Acta 1076, 165-172. 

The iron-sulfur cluster is often present as the prosthetic group in oxidoreductases where the couple of the substrate is below 0 mV. This reflects the reducing power of the iron-sulfur cluster. There are, however, a small number of iron-sulfur-containing enzymes that function in the positive redox range. These are often associated with bacterial nitrate and nitrite metabolism. The least complicated enzymes contain no additional cofactor, while others contain a number of additional cofactors. 

Iron-sulfur-containing proteins are ubiquitously present in nature, where they exert a broad range of functions (cf. Table 1). Some of these functions can be defined as catalytic, and these have been addressed in this chapter. 

In 1984, Hibbs, Taintor, and Vavrin reported that CAMs cause L1210 cells to lose up to 64% of their intracellular iron, and the time course of this release is similar to that of CAM-induced mitochondrial inhibition In 1986, Drapier and Hibbs " showed that aconitase (an iron-sulfur-containing enzyme (see Iron-Sulfur Proteins)) is also a target for CAM injury, and that the injured cells recover aconitase activity... 

The main objective of this article is to put together the information available on the novel iron-sulfur centers and relate their properties with those of the iron-sulfur containing proteins. Special effort is put on the techniques used to identify their centers and in the discussion of the oxidation-reduction potentials involved. 

Another example of this type of regulatory function of iron-sulfur-containing proteins can be found in the transcription factor FNR (/umarate nitrate reduction). 

Thorson jS. Liu H-W. Characterization of the fiist PMP-dependent iron-sulfur-containing enzyme which is essential for the biosynthesis of 3.6-dideoxyhexoses. ] Am Chem Sac 1993 115 7539-7540. 

We have attempted to divide this chapter into several main categories metal-free flavoproteins, hemoflavoproteins and iron-sulfur-containing flavoproteins, although the reader may And that due to overlap some sections appear where they might not have been expected. 

Enoate reductases (EC 1.3.1.31) are flavin-dependent and iron-sulfur-contain-ing proteins found among others in Clostridium species. Members of this NADHrflavin oxidoreductase/NADH oxidase family are distinguished from other ERs due to their high stereospecificity and strict regioselectivity for the reduction of double bonds of monoacids and monoesters, as well as reducing classical substrates such as a,p-unsaturated aldehydes, cyclic ketones, and methyl ketones. However, these enzymes are extremely oxygen sensitive, so they have not been employed in biocatalysis so far [2,3]. 

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