Enzymatic methylation of sulfide, selenide, and organic thiols by Tetrahymena thermophila

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · Appl. Environ. Microbiol.; (United States)

OSTI ID:5927105

Drotar, A; Fall, L R; Mishalanie, E A; Tavernier, J E; Fall, R

Cell extracts from the ciliate Tetrahymena thermophila catalyzed the S-adenosylmethionine-dependent methylation of sulfide. The product of the reaction, methanethiol, was detected by a radiometric assay and by a gas-chromatographic assay coupled to a sulfur-selective chemiluminescence detector. Extracts also catalyzed the methylation of selenide, and the product was shown by gas chromatography-mass spectrometry to be methaneselenol. The sulfide and selenide methyltransferase activities copurified with the aromatic thiol methyltransferase previously characterized from this organism, but heat inactivation experiments suggested the involvement of distinct sulfide and selenide methyltransferases. Short-term toxicity tests were carried out for sulfide, selenide, and their methylated derivatives; the monomethylated forms were somewhat more toxic than the nonmethylated or dimethylated compounds. Cell suspensions of T. thermophila exposed to sulfide, methanethiol, or their selenium analogs emitted methylated derivatives into the headspace. These results suggest that this freshwater protozoan is capable of the stepwise methylation of sulfide and selenide, leading to the release of volatile methylated sulfur or selenium gases.

• Research Organization: Univ. of Colorado, Boulder
• OSTI ID: 5927105
• Journal Information: Appl. Environ. Microbiol.; (United States), Vol. 53:9
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
METHYL TRANSFERASES
ENZYME ACTIVITY
SELENIDES
METHYLATION
TOXICITY
SULFIDES
THIOLS
CHEMILUMINESCENCE
GAS CHROMATOGRAPHY
MASS SPECTROSCOPY
RADIOASSAY
TETRAHYMENA
TRACER TECHNIQUES
ANIMALS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMATOGRAPHY
CILIATA
ENZYMES
INVERTEBRATES
ISOTOPE APPLICATIONS
LUMINESCENCE
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PROTOZOA
SELENIUM COMPOUNDS
SEPARATION PROCESSES
SPECTROSCOPY
SULFUR COMPOUNDS
TRANSFERASES
560300* - Chemicals Metabolism & Toxicology
550501 - Metabolism- Tracer Techniques