Biodegradation of Single-Walled Carbon Nanotubes by Eosinophil Peroxidase
2013 (English)In: Small, ISSN 1613-6810, Vol. 9, no 16, 2721-2729 p.Article in journal (Refereed) Published
Eosinophil peroxidase (EPO) is one of the major oxidant-producing enzymes during inflammatory states in the human lung. The degradation of single-walled carbon nanotubes (SWCNTs) upon incubation with human EPO and H2O 2 is reported. Biodegradation of SWCNTs is higher in the presence of NaBr, but neither EPO alone nor H2O2 alone caused the degradation of nanotubes. Molecular modeling reveals two binding sites for SWCNTs on EPO, one located at the proximal side (same side as the catalytic site) and the other on the distal side of EPO. The oxidized groups on SWCNTs in both cases are stabilized by electrostatic interactions with positively charged residues. Biodegradation of SWCNTs can also be executed in an ex vivo culture system using primary murine eosinophils stimulated to undergo degranulation. Biodegradation is proven by a range of methods including transmission electron microscopy, UV-visible-NIR spectroscopy, Raman spectroscopy, and confocal Raman imaging. Thus, human EPO (in vitro) and ex vivo activated eosinophils mediate biodegradation of SWCNTs: an observation that is relevant to pulmonary responses to these materials. Human eosinophil peroxidase (EPO) is able to degrade SWCNTs in vitro in the presence of H2O2. EPO is one of the major oxidant-generating enzymes present in human lungs during inflammatory states. The biodegradation of SWCNTs is evidenced also in an ex vivo culture system using primary murine eosinophils stimulated to undergo degranulation. These results are relevant to potential respiratory exposure to carbon nanotubes.
Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2013. Vol. 9, no 16, 2721-2729 p.
biodegradable materials, carbon nanotubes, eosinophil peroxidase, molecular modeling, Biodegra-dable materials, Catalytic sites, Confocal Raman imaging, Culture systems, Oxidized groups, Positively charged, Single-walled carbon nanotube (SWCNTs), Enzymes, Microbiology, Near infrared spectroscopy, Oxidants, Respiratory system, Single-walled carbon nanotubes (SWCN), Transmission electron microscopy, Biodegradation
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-133837DOI: 10.1002/smll.201202508ISI: 000327738600011ScopusID: 2-s2.0-84879786954OAI: oai:DiVA.org:kth-133837DiVA: diva2:663856
FunderFormasEU, FP7, Seventh Framework Programme, 263215
QC 201311132013-11-132013-11-112014-01-13Bibliographically approved