Purification, sequencing and characterization of rabbit liver arsenite and methylarsonic acid methyltransferase

摘要: Inorganic arsenic is an important environmental toxicant of both natural and anthropogenic sources. It a human carcinogen for which appropriate animal models most arsenic-induced cancers are lacking. Presently, 17 species non-human primates were screened using in vitro assay to determine their methylation ability as predictive tool better understanding the presence, some instances, deficiency methyltransferase activity among species. Four investigated had arsenite activity, three from genus Macaco. This suggested phylogenetic component having activity. That all hepatic tissues viable was demonstrated by arsenate reductase These data that cannot be detoxification mechanism many alternative methods detoxifying inorganic must considered investigated. Biomethylation has classically been its primary detoxification, although results recent investigations disagree. As may represent bioactivation process leading cancer development, it now becomes critical identify protein, endogenous function, well additional substrates inhibitory molecules. Using combination chromatographic isoelectric focusing protein separation methods, rabbit liver methylarsonic acid activities purified 19,000and 600-fold, respectively. co-purified during steps. The molecular mass approximately 46.5 kDa pi 5.7 6.0 inhibited Sadenosyl-L-homocysteine, sinefungin trivalent antimony. final fraction contained heterogeneous mixture assessed SDS-PAGE analysis. Proteins this identified tandem matrix-assisted laser desorption/ionization spectrometry techniques against databases known proteins. Identified