Here, we report on the facilitated reactivation (85%) of oxidatively inactivated rhodanese by an oxidized form of the molecular chaperone GroEL (ox-GroEL). Reactivation by ox-GroEL required a reductant, and the enzyme substrate, sodium thiosulfate. Also, we found that ox-GroEL formed a complex with oxidatively inactivated rhodanese as shown by differential centrifugation and fluorescence spectr...

The structure of the rhodanese-tetracyanonickelate (E X Ni(CN)2-4) complex has been characterized here in spectral and physical studies using urea as a structural perturbant. UV difference absorption, sedimentation velocity ultracentrifugation, fluorescence, and circular dichroism data show no significant conformational differences between sulfur-free rhodanese (E) and the E X Ni(CN)2-4 complex...

Selenophosphate, an activated form of selenium that can serve as a selenium donor, is generated by the selD gene product, selenophosphate synthetase (SPS). Selenophosphate is required by several bacteria and by mammals for the specific synthesis of Secys-tRNA, the precursor of selenocysteine in selenoenzymes. Although free selenide can be used in vitro for synthesis of selenophosphate, the phys...

The wobble nucleoside 5-methylaminomethyl-2-thio-uridine (mnm5s2U) is present in bacterial tRNAs specific for Lys and Glu and 5-carboxymethylaminomethyl-2-thio-uridine (cmnm5s2U) in tRNA specific for Gln. The sulfur of (c)mnm5s2U may be exchanged by selenium (Se)-a reaction catalyzed by the selenophosphate-dependent tRNA 2-selenouridine synthase encoded by the mnmH (ybbB, selU, sufY) gene. The ...

It is known that cyanide is converted to thiocyanate in the presence of the enzyme rhodanese. The enzyme is activated by sulfur transfer from an appropriate sulfur donor. The activated enzyme then binds cyanide and transfers the sulfur atom to cyanide to form thiocyanate. This project began as an exploration of the ability of disulfides to act as sulfur donors in the rhodanese-mediated detoxifi...

Cyanide detoxification is catalysed by two enzymes: rhodanese [thiosulphate: cyanide sulphurtransferase, E.C. 2.8.1.1], and 3-mercaptopyruvate sulphurtransferase [3-MST, EC. 2.8.1.2]. In the present work, the activity of the two enzymes in the crude extracts of different tissues and in the mitochondrial and cytosolic fractions of tissues from some ruminants (camels, cattle and sheep) and birds ...

Rhodanese (thiosulphate : cyanide sulphur-transferase; EC 2 . 8 . I . I) was originally ,described by Lang (1933). The enzyme catalyses the formation of thiocyanate from cyanide and thiosulphate according to the reaction : S20!+ CN-+ SCN+ SO:-. Rhodanese activity has been demonstrated in most mammalian tissues, with the greatest activity present in liver and kidney. The enzyme has been purified...

PspE, encoded by the last gene of the phage shock protein operon, is one of the nine proteins of Escherichia coli that contain a rhodanese homology domain. PspE is synthesized as a precursor with a 19-amino acid signal sequence and secreted to the periplasm. Mature PspE is the smallest rhodanese of E. coli (85 amino acids) and catalyzes the transfer of sulfur from thiosulfate to cyanide forming...