Biotransformation and biomethylation of arsenic by. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. Chemical mechanism of arsenic biomethylation william r. Frontiers microbially mediated methylation of arsenic in. Arsenic biomethylation by photosynthetic organisms cell press. Controlled variation of redox conditions in a floodplain soil. Pdf recent research of the metabolism and biological effects of arsenic has profoundly changed our understanding of the role of metabolism. Biomethylation is the pathway for converting some heavy elements into more mobile or more lethal derivatives that can enter the food chain. However, in all the previous studies each metalloid was studied in isolation. Introdctiona century of study of the process by which many organisms convert inorganic arsenic into an array of methylated metabolites has answered many questions and has posed some new ones. A semicontinuous hydride generationgas chromatographyatomic absorption spectrometry hggcaa system was developed and optimized for the determination of arsenite, arsenate, methylarsonate mma, dimethylarsinate dma, and trimethylarsine oxide tmao. Requirement of arsenic biomethylation for oxidative dna damage. Arsenic biomethylation by photosynthetic organisms request pdf.
Biomethylation and volatilization of arsenic by model. Mouse strain variability may provide a better understanding of. The bioconversion of inorganic arsenic to methylated metabolites a. To address these issues, we collected 9 arsenic rich soilsediment samples from the depths of 1, 30, 65, 95, 114, 5, 175, 200, and 223. While arsenic is most well known as a poison and indeed the contamination of groundwater by arsenic is becoming a major health problem in asia it also has uses for the treatment of blood cancer and has long been used in. Biomethylation of as has implications for its mobility and toxicity. Source, distribution, toxicity and remediation of arsenic in the. Nov 14, 2010 while arsenic is most well known as a poison and indeed the contamination of groundwater by arsenic is becoming a major health problem in asia it also has uses for the treatment of blood cancer and has long been used in traditional chinese medicine. Requirement of arsenic biomethylation for oxidative dna. Biomethylation of arsenic takes place with the help of various species of microand. Rosen3 and yongguan zhu1,4 1key laboratory ofurbanenvironment and health, institute environment, chinese academy sciences, xiamen 361021. The halflife of inorganic arsenic in humans is about 10 hours rossman 2007. Biological chemistry of arsenic, antimony and bismuth wiley.
Niehs researchers have found that biomethylation of arsenic compounds, previously considered to be a detoxification mechanism, actually appears to cause oxidative dna damage and to increase arsenic carcinogenicity. Arsenic trioxide is only slightly soluble in water. Biomethylation of arsenic, antimony and bismuth biological. Tetrahymena pyriformis, a freshwater protozoan, is common in aquatic systems. Volatilization of arsenic in environmental chemistry of. Photosynthetic organisms may play a significant role in as geochemical cycling by methylating it to different as species, but little is known about the mechanisms of. Thus, trivalent inorganic arsenic compounds are methylated to give methanearsonate. Requirement of arsenic biomethylation for oxidative dna damage article pdf available in journal of the national cancer institute 10124. For arsenic, the major volatile compounds formed by biomethylation have the structure, ch 3 nash 3n. Inorganic arsenic is known to be carcinogenic to humans and is a common contaminate in drinking water. Arsenic methylation and its relationship to abundance and. Singh and amitava rakshit department of soil science and agricultural chemistry, institute of agricultural science, banaras hindu university, 221005 varanasi, uttar pradesh, india abstract arsenic becomes a serious problem in this era. Substantial contribution of biomethylation to aquifer.
Arsenic metabolic pathways including cellular accumulation, ef. Arsenic biomethylation required for oxidative dna damage. Ecological soil screening levels ecossls are concentrations of contaminants in soil that are protective of ecological receptors that commonly come into contact with andor consume biota that live in or on soil. The bioconversion of inorganic arsenic to methylated metabolites affects the tissue distribution and retention of arsenic and its. Arsenic is a chemical element with the symbol as and atomic number 33.
Arsenic, antimony and bismuth, three related elements of group 15, are all found in trace quantities in nature and have interesting biological properties and uses. Arsenic and antimony biomethylation by scopulariopsis. This ms is useful to the general scientific field as it integrates data from diverse organisms to provide a coherent view of the molecular aspects of arsenic methylation. Pdf requirement of arsenic biomethylation for oxidative dna. Cullen department of chemistry, university of british columbia, vancouver, british columbia, canada v6t 1z1 abstract.
Pdf substantial contribution of biomethylation to aquifer. Biotransformation and biomethylation of arsenic by shewanella. The term biomethylation describes the formation of both volatile and nonvolatile methylated compounds of metals and metalloids. Subsequent detection of methylated arsenicals in natural waters and in human urine suggested that biomethylation of arsenic was a widespread phenomenon cullen, 2008. Arsenic detoxification through biotransformation by t. The symptoms of arsenic exposure are a perfect example of the doseresponse relationship. Oct 01, 2002 however, compelling experimental evidence obtained from several laboratories suggests that biomethylation, particularly the production of methylated metabolites that contain trivalent arsenic, is a process that activates arsenic as a toxin and a carcinogen. There is ample evidence of biomethylation in the soil and of the release of methylarsines into the air. Miroslav styblo, zuzana drobna, ilona jaspers, shan lin, and david j thomas department of pediatrics, center for environmental medicine and lung biology, burnettwomack clinical sciences building, university of north carolina, chapel hill, nc 27599. Chemical mechanism of arsenic biomethylation american.
The full text of this article is available as a pdf 236k. Review acute and chronic arsenic toxicity r n ratnaike postgrad med j 2003. Based on these results, we estimate that globally, biomethylation in aquifers has the potential to transform 100 tons of inorganic arsenic to methylated arsenic species per year, compared with the. The microorganism apiotrichum humicola previously known as candida humicola grown in the presence of either arsenate, arsenite, methylarsonic acid or dimethylarsinic acid, produces arsenic containing metabolites in the growth medium. The role of biomethylation in toxicity and carcinogenicity of. Substantial contribution of biomethylation to aquifer arsenic cycling article pdf available in nature geoscience 8april. Arsenic and antimony are often associated in the environment, and so an understanding of interactions between these elements is necessary. Interactive effects of n6amt1 and as3mt in arsenic biomethylation. Arsenic toxicity csem agency for toxic substances centers for.
Arsenic biomethylation by photosynthetic organisms. The resistance of shewanella oneidensis mr1 to toxic arsenic was investigated by measuring the growth of the bacteria in the presence of asiii and asv in different growth media. Nov 15, 2010 summary this chapter contains sections titled. Strain differences in arsenicinduced oxidative lesion via. Arsenic naturally occurs as sulfides and as complex sulfides of iron, nickel, and cobalt woolson 1975. Pdf requirement of arsenic biomethylation for oxidative. Based on these results, we estimate that globally, biomethylation in aquifers has the potential to transform 100 tons of inorganic arsenic to methylated arsenic species per. There is ample evidence of biomethylation in the soil and of. Almost nothing is known about the activities and diversities of microbial communities involved in as methylation in arsenic rich shallow and deep sediments.
The biomethylation of arsenic ubc library open collections. Arsenic biomethylation by photosynthetic organisms jun ye1, christopher rensing2, barry p. Ecossls are derived separately for four groups of ecological receptors. Dermal absorption also occurs, but to a lesser extent. The metabolism of inorganic arsenic ias in humans involves two types of chemical reactions, the reduction of pentavalent arsenicals to trivalency and the. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Oct 01, 2009 the primary routes of arsenic entry into the body are ingestion and inhalation. For arsenic, the major volatile compounds formed by biomethylation have the structure, ch 3 n ash 3. Arsenic as is a ubiquitous element that is widespread in the environment and causes numerous health problems. Photosynthetic organisms may play a significant role in as geochemical cycling by methylating it to different as species, but little is known about the mechanisms of methylation. Mar 09, 2015 based on these results, we estimate that globally, biomethylation in aquifers has the potential to transform 100 tons of inorganic arsenic to methylated arsenic species per year, compared with the. Key words arsenic, methylation, glutathione, dimethylarsinic acid. Arsenic is clearly carcinogenic in humans and has multiple in vivo targets that include the skin, lung, bladder, prostate, and liver, although the carcinogenic mechanisms remain incompletely defined 1,2.
Arsenic metabolic pathways including cellular accumulation, effluxion, biomethylation, and volatilization of t. Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water and may also occur from mining and other industrial. Substantial contribution of biomethylation to aquifer arsenic. Introduction biomethylation of arsenic biomethylation of antimony biomethylation of bismuth abbreviations references biomethylation of arsenic, antimony and bismuth biological chemistry of arsenic, antimony and bismuth wiley online library. The bacteria were shown to biotransform arsenic through the partial methylation of inorganic arsenic into methylated metabolites. Epa banned residential uses of arsenic based wood preservatives in 2004. Soil arsenic levels are normally elevated near arseniferous deposits, and. However, compelling experimental evidence obtained from several laboratories suggests that biomethylation, particularly the production of methylated metabolites that contain trivalent arsenic, is a process that activates arsenic as a toxin and a carcinogen. The alga seems to follow the biomethylation pathway proposed by challenger for microbial process, and in the case of p. Particularly, this system was used to study the pathway for the biomethylation of arsenicals in microorganisms and a marine alga.
Biomethylation of arsenic is essentially detoxicating event. Mar 17, 2017 arsenic is a common environmental and occupational toxicant with dramatic species differences in its susceptibility and metabolism. Frankenberger and others published volatilization of arsenic in environmental chemistry of arsenic find, read and cite all the research you need on researchgate. The enzymology of arsenic biomethylation is complicated by the several oxidation states for this element, the previously discussed propensity of arsenic to react with sulfur compounds, and the fact that only very small amounts of the arsenic compounds are present in biological specimens. Pdf arsenic biomethylation by the microorganismapiotrichum. Approximately 70% of arsenic is excreted, mainly in urine rossman 2007. Pdf biomethylation and volatilization of arsenic by. The chemistry and metabolism of arsenic science inventory. Impact on metal mobilization and biomethylation of arsenic and antimony.
Pdf the role of biomethylation in toxicity and carcinogenicity of. May 02, 2000 the biomethylation of arsenic by the filamentous fungus scopulariopsis brevicaulis is well documented, and the biomethylation of antimony by this fungus was recently established. Arsenic concentrations in uncontaminated soil are generally in the range 0. In one form or another, arsenic is present in rocks, soils, water, and living organisms at concentrations of parts per billion to parts per million nas 1977. Arsenic methyltransferase science inventory us epa. The biomethylation of arsenic compounds starts with the formation of methanearsonates.
1465 1137 1391 291 544 581 1405 223 1266 1421 1545 946 613 832 788 86 999 474 559 335 691 357 18 1023 793 6 126 629 359 690 1340 1275 298 1086 354 736 211 370 788 333 1181 17 446 30 956 252 1168