摘要:Methylcobalamin (methyl-B12) has been implicated in the biomethylation of the heavy metals (mercury, tin, platinum, gold, and thallium) as well as the metalloids (arsenic, selenium, tellurium and sulfur). In addition, methylcobalamin has been shown to react with lead, but the lead-alkyl product is unstable in water. Details of the kinetics and mechanisms for biomethylation of arsenic are presented, with special emphasis on synergistic reactions between metal and metalloids in different oxidation states. This study explains why synergistic, or antagonistic, processes can occur when one toxic element reacts in the presence of another. The relative importance of biomethylation reactions involving methylcobalamin will be compared to those reactions where S-adenosylmethionine is involved. Full text Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (558K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References . 43 44 45 46