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

Journal Article · Tue Sep 01 04:00:00 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), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 53:9; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

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