Open AccessIsolation of the Tetrathionate Hydrolase from Thiobacillus Acidophilus
Author(s) -
Jong Govardus A. H.,
Hazeu Wim,
Bos Piet,
Kuenen J Gijs
Publication year - 1997
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1997.00678.x
Subject(s) - tetrathionate , chemistry , thiosulfate , enzyme , cofactor , enzyme assay , sulfur , rhodanese , chromatography , biochemistry , inorganic chemistry , organic chemistry
An enzyme capable of hydrolysing tetrathionate was purified from cell‐free extracts of Thiobacillus acidophilus. The purified enzyme converts tetrathionate into thiosulfate, sulfur and sulfate. In addition, pentathionate could also be converted by the same enzyme. Measurement of the enzyme activity during purification is based on the absorbance of the initial intermediates formed from tetrathionate in the ultraviolet region, which have not been identified. Enzyme activity could also be measured by the scattering of insoluble sulfur in the visible region. The purified enzyme has a pH optimum of 2.5 and a temperature optimum of 65°C. Enzyme activity is strongly stimulated by the presence of sulfate ions. The purified enzyme is a dimer with two identical subunits of 48kDa. The ultraviolet–visible absorption spectra and denaturation experiments indicate the presence of an organic cofactor.