Rhodanese Activity Research Articles

Demonstration of Rhodanese Activity in Polyacrylamide Gels

Rhodanese activity from crude extracts of Thiobacillus sp. strain IV-85 was demonstrated in polyacrylamide gels after incubation in the reaction mixture by staining with dichloroindophenol in the presence of methylphenazonium methosulfate. The sensitivity of the staining system was found to be 8 × 10 -7 moles of sulfite.

Demonstration of Rhodanese Activity in Polyacrylamide Gels

Rhodanese activity from crude extracts of Thiobacillus sp. strain IV-85 was demonstrated in polyacrylamide gels after incubation in the reaction mixture by staining with dichloroindophenol in the presence of methylphenazonium methosulfate. The sensitivity of the staining system was found to be 8 x 10 moles of sulfite.

Rhodanese of tapioca leaf

Rhodanese activity was detected in a crude extract of tapioca ( Manihot utilissima) leaves. Optimal activity was found at a high pH (10·2–11·0) and temperature (57–59°). Under these conditions, rhodanese from 0·5 ml of the crude extract (75 mg leaf fr. wt.) catalysed the formation of 10·2 μmoles thiocyanate per 15 min.

Observations on the rhodanese activity of Desulfotomaculum nigrificans.

Rhodanese activity, partially purified from Desulfotomaculum nigrificans, was shown to reside in a protein fraction separate from thiosulfate reductase.

Survey of the Photosynthetic Bacteria for Rhodanese (Thiosulfate: Cyanide Sulfur Transferase) Activity

Rhodanese activity was demonstrated in extracts from all three taxonomic families of photosynthetic bacteria, and this activity appeared to be uncorrelated with thiosulfate metabolism.

Studies on the Active Site of Rhodanese

Abstract The complete loss of enzymic activity on reaction with alkylating agents, aromatic nitro compounds, or aliphatic mercaptans indicates the importance of sulfhydryl groups for catalysis. Analyses during the course of inactivation with any of these reagents revealed the loss of one of the two —SH groups in the rhodanese monomer when inactivation was complete. Amino acid analysis of iodoacetate-inactivated enzyme showed that half its cysteine residues had been carboxymethylated. Sedimentation experiments showed that dinitrobenzene-inactivated enzyme was an oxidized dimer, indicating the formation of an intermolecular disulfide bond between monomers. Reduction of mercaptoethanol-inactivated enzyme resulted in the appearance of two —SH-groups, suggesting the existence of a mixed disulfide of the reagent and the enzyme. In addition, competitive inhibition of rhodanese activity by aromatic ions, but not by the corresponding aliphatics, supported previous evidence suggesting the presence of a tryptophanyl residue at the active center. Further results suggested close proximity of the essential sulfhydryl and aromatic groups in the active site of rhodanese.

The arginase and rhodanese activities of certain cell strains after long cultivation in vitro.

The activities of the enzymes arginase and rhodanese were examined in homogenates of 13 mouse cell strains and 2 human cell strains after long cultivation of the cells in vitro. Three strains of mouse liver origin showed both high arginase and rhodanese activities in keeping with activities of the tissue of origin. Two strains of cells of human epithelial origin, HeLa and epidermis, were found to have high rhodanese activity but low arginase activity, the skin being almost devoid of it. Seven mouse fibroblast strains or substrains had moderate rhodanese activity and all except one of the strains had low arginase activity. Two of the fibroblast strains tested, NCTC 1745 and NCTC 2050, were derived from a single cell of a tumor appearing after injection of the high tumor producing strain NCTC 1742 into a mouse. The strain 1745 had 20 times and the strain 2050 had 400 times the arginase activity of the parent strain of cells. The findings imply a considerable biochemical variation in the three strains. Three mouse mammary carcinoma clones were devoid of arginase activity, but had considerable rhodanese activity.

Rhodanese Activity of Resting, Regenerating, and Neoplastic Liver Tissue of the Rat<xref ref-type="fn" rid="fn1">1</xref>, <xref ref-type="fn" rid="fn2">2</xref>

Rhodanese Activity of Resting, Regenerating, and Neoplastic Liver Tissue of the Rat<xref ref-type="fn" rid="fn1">1</xref>, <xref ref-type="fn" rid="fn2">2</xref>