Succinic dehydrogenase and

Wachtershanser has also suggested that early metabolic processes first occurred on the surface of pyrite and other related mineral materials. The iron-sulfur chemistry that prevailed on these mineral surfaces may have influenced the evolution of the iron-sulfur proteins that control and catalyze many reactions in modern pathways (including the succinate dehydrogenase and aconitase reactions of the TCA cycle). 

Van Der Laarse, W.J., LSnnergren, J., Diegenbach, P.C. (1991). Resistance to fatigue of single muscle fibers from Xenopus related to succinate dehydrogenase and myofibrillar ATPase activities. Exp. Physiol. 76, 589-596. 

All these components are in the inner membrane of the mitochondria as shown in Figure I-I3-3. Succinate dehydrogenase and the a-glycerol phosphate shuttle enzymes reoxidize their FADHj and pass electrons directly to CoQ. 

As described elsewhere in this chapter, alterations in the activity of a number of lung enzymes have been described after acute and chronic ozone exposure. With the possible exceptions of the sulfhydryl-containing enzyme succinic dehydrogenase and the cytochrome P-4 en me benzopyrene hydroxylase, it is difficult to determine whether these findings are due to a direct oxidative effect of ozone or are secondary to changes in protein synthesis, concentrations of intermediates, or destruction of cells or organelles. 

Freebaim noted a decrease in oxygen uptake of plant and bovine liver mitochondria that was reversible by glutathione and ascorbic acid. The activity of some mitochondrial enzymes, including succinic dehydrogenase and cytochrome oxidase, has been found to be susceptible to ozone. 

Administration of 1 and 3 mg Sn/kg body weight to rats resulted in inhibition of various enzymes, including hepatic succinate dehydrogenase and the acid phosphatase of the femoral epiphysis. Tin also appears to interact with the absorption and metabolism of biological essential metals such as copper, zinc, and iron and to influence heme metabolism. ... 

Increase in activity of cerebral succinic dehydrogenase and brain acid proteinase, and in brain RNA concentration decrease in liver cytochrome P-450 activity (22)... 

A very useful complement to enzyme assays as described above is histochemical study, which can provide additional information [76]. In particular, because it is possible to measure the activity cell per cell, histochemistry permits, in the case of a heteroplasmic population of mitochondria, the detection of even a small number of affected cells, which may have remained undetected by biochemical assays. Spectacular images showing, side-by-side, cells endowed with either high or absent enzyme activity can be obtained. The limitation of the method is in part due to the few activities possibly measured (essentially complex IV, succinic dehydrogenase, and less specifically, ATPase and NADH reductase) and to the fact that it is poorly quantitative. Histochemical investigations are performed under selected conditions (e.g., substrate concentrations, pH), which often differ from those used for enzyme assays, thus possibly introducing discrepancy between the two approaches. 

Ackrell, B. A. C., McIntire, W., Edmondson, D. E., Kearney, E. B. The semiquinone form of succinate dehydrogenase and other Sa-substituted flavoenzymes. In Flavins and flavoproteins (Massey, V., Williams, C. H. eds.) pp. 488-491, New York, Amsterdam, Oxford, Elsevier/North Holland 1982... 

Architecture of succinate dehydrogenase and reactive oxygen species generation. Science 299, 700-704. 

Aluminum May activate succinic dehydrogenase and 6-aminolevuimate de-hydrase. The latter is involved in porphyrin synthesis/... 

Because the enzymes of the citric acid cycle203 (with the exception of succinate dehydrogenase) and (3 oxidation are present in the matrix, the reduced electron carriers must approach the inner membrane from... 

Aspartate can be deaminated to fumarate by bacterial L-aspartate oxidase.2593 This flavoprotein is structurally and mechanistically related to succinate dehydrogenase and can function as a soluble fumarate reductase (p. 1027). However, its main function appears to be to permit the intermediate iminoaspartate to react with dihydroxyacetone-P to form quinolinate, which can be converted to NAD (see Fig. 25-ll).259b... 

Fumarate is able to serve as an electron acceptor in anaerobic respiration, as it may be reduced reversibly to succinate in a two-electron process. The succinate-fumarate couple may therefore be utilized as an oxidant or reductant in the respiratory chain, and so differs from the other examples given in this section. These two reactions are catalyzed by succinate dehydrogenase and fumarate reductase, which have many similarities in subunit structure. These are shown in Table 29. Although they are different enzymes, the fumarate reductase can substitute for succinate dehydrogenase under certain conditions. The synthesis of succinate dehydrogenase is induced... 

Complex II consists of four polypeptide subunits (70,000, 27,000, 13,500, and 7,000 daltons). The two larger subunits are components of succinate dehydrogenase and this enzyme or the entire complex II was directly incorporated into phospholipid vesicles at the high protein lipid ratio of 1 2 (w/w). The phospholipid (egg yolk lecithin) contained a small amount of lipid (d) (Table 6.2 I molecule in 1000) or lipid (e) (Table 6.2 1 in 400). After irradiation the labeling pattern was analyzed directly by SDS-polyacrylamide gel electrophoresis. Presumably the lipids that did not become attached to polypeptides ran at the dye front, although this was not demonstrated. 

Succinate dehydrogenase and cytochrome oxidase in adult and plerocercoid Diphyllobothrium latum. Comparative Biochemistry and Physiology, 49B 87-92. 

Ackrell BAC, Johnson MK, Gunsalus RP, Cecchini G (1992) Structure and function of succinate dehydrogenase and fumarate reductase. In Muller F (ed) Chemistry and biochemistry of flavoenzymes, vol III. CRC, Boca Raton, pp 229-297 Allen PC (1973) Helminths comparison of their rhodoquinone. Exp Parasitol 34 211-219... 

Dihydroflavonols. Widely distributed 2,3-dihydroflavon-3-ols include the antioxidant 2,3-dihydroflavonols aromadendrin (3,5,7,4 -tetrahydroxyflavanone 2,3-dihydrokaempferol), ampelopsin (3,5,7,3, 4, 5 -hexahydroxyflavanone 2,3-dihydromyricetin), fustin (3,7,3, 4 -tetrahydroxyflavanone 2,3-dihydrofisetin) and taxifolin (3,5,7,3, 4 -pentahydroxy-flavanone 2,3-dihydroquercetin). Some flavanols are sweet-tasting, notably 6-methoxy-aromadendrin 3-O-aceate, 6-methoxytaxifolin and taxifolin 3-0-acetate. Taxifolin and fustin inhibit NADH and succinate dehydrogenases and taxifolin inhibits 5-LOX. 

Henriksson, J. and Reltman, J. S. (1977) Time course of changes In human skeletal muscle succinate dehydrogenase and cytochrome oxidase activities and maximal oxygen uptake with physical activity and inactivity. Acta Physiol. Scand. 99 91-7. 

---