OBJECTIVES Thiopurine compounds are commonly used in the treatment of childhood acute lymphoblastic leukemia, and as immunosuppressants following organ transplantation or for treatment of various autoimmune disorders. Thiopurine S-methyltransferase (TPMT) is required for detoxification, through S-methylation, of 6-thioguanine nucleotides (TGNs), a byproduct of thiopurine metabolism. Single nucl...

The methylation of norepinephrine to epinephrine was first demonstrated by Biilbring with the use of minced adrenal gland and adenosine triphosphate (2). Soon after, Keller, Boissonnas, and du Vigneaud (3) showed that the methyl group of methionine is incorporated into the epinephrine of the adrenal gland in the intact animal. Subsequently, S-adenosylmethionine was shown to be the methyl donor ...

I. Aetna considers TPMT gene mutation or TPMT phenotypic assays (e.g., Prometheus TPMT Genetics, Prometheus TPMT Enzyme) medically necessary prior to initiation of 6mercaptopurine or azathioprine therapy. Only 1 genotypic or phenotypic assay of TPMT activity is necessary per member per lifetime. TPMT gene mutation assays and TPMT phenotypic assays are considered experimental and investigational...

BACKGROUND Thiopurine S-methyltransferase (TPMT) enzyme metabolizes thiopurine drugs which are widely used in various disciplines as well as in leukemias. Individual enzyme activity varies depending on the genetic polymorphisms of TPMT gene located at chromosome 6. Up to 14% of population is known to have a decreased enzyme activity, and if treated with standard doses of thiopurines, these indi...

Escherichia coli cells expressing the tpm gene encoding the bacterial thiopurine methyltransferase (bTPMT) are shown to methylate selenite and (methyl)selenocysteine into dimethylselenide (DMSe) and dimethyldiselenide (DMDSe). E. coli cells expressing tpm from a gene library cosmid clone (harboring a Pseudomonas syringae insert of about 20 kb) also methylated selenate into DMSe and DMDSe. bTPMT...

Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine (6-MP), thioguanine and azathioprine (AZA). These drugs are used to treat conditions such as acute lymphoblastic leukemia, inflammatory bowel disease, rheumatoid arthritis, and organ transplant rejection. This review highlights the polymorphisms of TPMT gene and their clinical impact on ...

Involvement of the bacterial thiopurine methyltransferase (bTPMT) in natural selenium methylation by freshwater was investigated. A freshwater environment that had no known selenium contamination but exhibited reproducible emission of dimethyl selenide (DMSe) or dimethyl diselenide (DMDSe) when it was supplemented with an organic form of selenium [(methyl)selenocysteine] or an inorganic form of...