1. A method is described for extracting separately mitochondrial and extramitochondrial enzymes from fat-cells prepared by collagenase digestion from rat epididymal fat-pads. The following distribution of enzymes has been observed (with the total activities of the enzymes as units/mg of fat-cell DNA at 25°C given in parenthesis). Exclusively mitochondrial enzymes: glutamate dehydrogenase (1.8),...

Friedreich ataxia (FA), the most common form of hereditary ataxia, is caused by a deficit in the mitochondrial protein frataxin. While several hypotheses have been suggested, frataxin function is not well understood. Oxidative stress has been suggested to play a role in the pathophysiology of FA, but this view has been recently questioned, and its link to frataxin is unclear. Here, we report th...

Dual localization of proteins in the cell has appeared in recent years to be a more abundant phenomenon than previously reported. One of the mechanisms by which a single translation product is distributed between two compartments, involves retrograde movement of a subset of processed molecules back through the organelle-membrane. Here, we investigated the specific contribution of the mitochondr...

Mixed ruminal bacteria convert trans-aconitate to tricarballylate, a tricarboxylic acid which chelates blood divalent cations and decreases their availability (J. B. Russell and P. J. Van Soest, Appl. Environ. Microbiol. 47:155-159, 1984). Decreases in blood magnesium in turn cause a potentially fatal disease known as grass tetany. trans-Aconitate was stoichiometrically reduced to tricarballyla...

Studies with deuterium as a tracer have shown that wheat germ and pig heart malic dehydrogenase act on the keto form of oxaloacetic acid (1, 2). The keto form of this acid has also been shown to arise in the enzymatic carboxylation of phosphorylenolpyruvate by wheat germ phosphoryl-enolpyruvate carboxylase (3) and by avian liver phosphoryl-enolpyruvate carboxylase kinase (2). In an attempt to e...

Itaconic acid is an important biomass-derived chemical building block but has also recently been identified as a metabolite produced in mammals, which has antimicrobial activity. The biosynthetic pathway of itaconic acid has been elucidated in the ascomycetous fungus Aspergillus terreus and in human macrophages. In both organisms itaconic acid is generated by decarboxylation of the tricarboxyli...

Altekar, W. W. (National Chemical Laboratory, Poona, India) and M. R. Raghavendra Rao. Microbiological dissimilation of tricarballylate and trans-aconitate. J. Bacteriol. 85:604-613. 1963.-Two fluorescent pseudomonads capable of metabolizing tricarballylate and trans-aconitate were isolated by the soil-enrichment culture technique. These and some other species of bacteria were tested for their ...

Bacteria from the bovine rumen capable of reducing trans-aconitate to tricarballylate were enriched in an anaerobic chemostat containing rumen fluid medium and aconitate. After 9 days at a dilution rate of 0.07 h, the medium was diluted and plated in an anaerobic glove box. Three types of isolates were obtained from the plates (a crescent-shaped organism, a pleomorphic rod, and a spiral-shaped ...