Biological and Biochemical Aspects of Tellurium Derivatives

Biological and biochemical studies of inorganic and organic complexes of tellurium are reviewed. Subject areas include the biosequestration and bioincorporation of tellurite and other inorganic tellurium compounds as well as tellurite-resistant bacteria. The incorporation of tellurium into amino acids (tellurocysteine) and the formation of unnatural glutathione peroxidases and thioredoxin reductases incorporating tellurocysteine are also described. Low molecular weight organotellurium compounds that mimic glutathione peroxidase and the thioredoxin reductases are discussed as are inorganic and organic tellurium compounds that inhibit cysteine proteases and related enzymes. The interactions of P-glycoprotein with organotellurium compounds to give stimulators and inhibitors of ATPase activity in the enzyme are described. The role of tellurium-containing chromophores in the photodynamic therapy of cancer and the photodynamic inactivation of viral and bacterial pathogens is also reviewed. The binding modes of tellurium-containing chromophores to DNA are also described.

Keywords: tellurite; organotellurides; diorgano ditellurides; inorganic tellurium complexes; glutathione peroxidase; thioredoxin reductase; tellurocysteine; P-glycoprotein; photodynamic therapy; anti-microbial activity