Gurd, Vars, and Ravdin (2) have shown that the restoration rate of liver protein following surgical removal of 70 per cent of the organ was greater in protein-depleted than in well nourished rats. These authors suggested that the stimulus to recovery of liver protein was more potent in the animal with the more severe reduction of liver substance. The nature of the stimulus to regeneration is no...

The individual reactions comprising the rhodanesecatalyzed thiosulfate-lipoate reaction were demonstrated kinetically. The mechanism was shown to be a reaction sequence in which the enzyme forms kinetically significant binary complexes with both thiosulfate and dihydrolipoate substrates. Moreover, the first product (sulfite) is discharged, forming a sulfur-substituted enzyme intermediate, befor...

Auxin is a plant hormone that regulates many aspects of plant growth and development. We used a chemical genetics approach to identify SIR1, a regulator of many auxin-inducible genes. The sir1 mutant was resistant to sirtinol, a small molecule that activates many auxin-inducible genes and promotes auxin-related developmental phenotypes. SIR1 is predicted to encode a protein composed of a ubiqui...

The non-cytotoxic concentration (20 μM) of menadione (2-methyl-1,4-naphthoquinone), after 1 h of incubation, leads to loss of the activity of rhodanese by 33%, 3-mercaptopyruvate sulfurtransferase by 20%, as well as the level of sulfane sulfur by about 23% and glutathione by 12%, in the culture of U373 cells, in comparison with the control culture. Reactive oxygen species generated by menadione...

Leber's hereditary optic neuropathy is a rare cause of progressive visual failure. Its cause is unknown, but one hypothesis is that patients have a defect in the detoxication of cyanide. One of the enzymes used in this detoxication is thiosulphate sulphurtransferase (rhodanese). The activity of this enzyme was measured in the rectal mucosa of a group of subjects with Leber's hereditary optic ne...

The non-cytotoxic concentration (20 microM) of menadione (2-methyl-1,4-naphthoquinone), after 1 h of incubation, leads to loss of the activity of rhodanese by 33%, 3-mercaptopyruvate sulfurtransferase by 20%, as well as the level of sulfane sulfur by about 23% and glutathione by 12%, in the culture of U373 cells, in comparison with the control culture. Reactive oxygen species generated by menad...

The 90 kDa heat shock protein (Hsp90) is a major cytoplasmic molecular chaperone associating with numerous other proteins. Both genetic and in vitro refolding experiments using reticulocyte lysate have suggested a functional interaction of Hsp90 with yeast human homologues of E. coli DnaJ. Here we present direct evidence using surface plasmon resonance that Hsp90 and the human DnaJ homologue, H...