The mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes

dc.contributor.authorEgan, Timothy J
dc.contributor.authorMavuso, Winile W
dc.contributor.authorNcokazi, Kanyile K
dc.date.accessioned2016-08-05T10:59:27Z
dc.date.available2016-08-05T10:59:27Z
dc.date.issued2001
dc.date.updated2016-08-01T09:15:04Z
dc.description.abstractFormation of â-hematin in acidic acetate solution has been investigated using quantitative infrared spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. The process occurs via rapid precipitation of amorphous (or possibly nanocrystalline) hematin, followed by slow conversion to crystalline â-hematin. Definitive evidence that the reaction occurs during incubation in acetate medium, rather than during the drying stage, is provided by X-ray diffraction and infrared spectroscopy of the wet material. The reaction follows a sigmoidal function indicative of a process of nucleation and growth and was modeled using the Avrami equation. Reaction rates and the dimensionality of growth (as indicated by the value of the Avrami constant) are strongly influenced by stirring rate. The reaction follows Arrhenius behavior, and there is a strong dependence of both the rate constant and the Avrami constant on acetate concentration. Acetate may act as a phase transfer catalyst, solubilizing hematin and facilitating its redeposition as â-hematin. The pH dependence of the process indicates that only the monoprotonated species of hematin is active in forming â-hematin. The formation of â-hematin closely parallels many mineralization processes, and this suggests that hemozoin formation may be a unique biomineralization process. Inferences are drawn with respect to the formation of hemozoin in vivo.en_ZA
dc.identifierhttp://dx.doi.org/10.1021/bi0013501
dc.identifier.apacitationEgan, T. J., Mavuso, W. W., & Ncokazi, K. K. (2001). The mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes. <i>Biochemistry</i>, http://hdl.handle.net/11427/21156en_ZA
dc.identifier.chicagocitationEgan, Timothy J, Winile W Mavuso, and Kanyile K Ncokazi "The mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes." <i>Biochemistry</i> (2001) http://hdl.handle.net/11427/21156en_ZA
dc.identifier.citationEgan, T. J., Mavuso, W. W., & Ncokazi, K. K. (2001). The mechanism of β-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes. Biochemistry, 40(1), 204-213.en_ZA
dc.identifier.issn0006-2960en_ZA
dc.identifier.ris TY - Journal Article AU - Egan, Timothy J AU - Mavuso, Winile W AU - Ncokazi, Kanyile K AB - Formation of â-hematin in acidic acetate solution has been investigated using quantitative infrared spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. The process occurs via rapid precipitation of amorphous (or possibly nanocrystalline) hematin, followed by slow conversion to crystalline â-hematin. Definitive evidence that the reaction occurs during incubation in acetate medium, rather than during the drying stage, is provided by X-ray diffraction and infrared spectroscopy of the wet material. The reaction follows a sigmoidal function indicative of a process of nucleation and growth and was modeled using the Avrami equation. Reaction rates and the dimensionality of growth (as indicated by the value of the Avrami constant) are strongly influenced by stirring rate. The reaction follows Arrhenius behavior, and there is a strong dependence of both the rate constant and the Avrami constant on acetate concentration. Acetate may act as a phase transfer catalyst, solubilizing hematin and facilitating its redeposition as â-hematin. The pH dependence of the process indicates that only the monoprotonated species of hematin is active in forming â-hematin. The formation of â-hematin closely parallels many mineralization processes, and this suggests that hemozoin formation may be a unique biomineralization process. Inferences are drawn with respect to the formation of hemozoin in vivo. DA - 2001 DB - OpenUCT DP - University of Cape Town J1 - Biochemistry LK - https://open.uct.ac.za PB - University of Cape Town PY - 2001 SM - 0006-2960 T1 - The mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes TI - The mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes UR - http://hdl.handle.net/11427/21156 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21156
dc.identifier.vancouvercitationEgan TJ, Mavuso WW, Ncokazi KK. The mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processes. Biochemistry. 2001; http://hdl.handle.net/11427/21156.en_ZA
dc.languageengen_ZA
dc.publisherAmerican Chemical Societyen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.sourceBiochemistryen_ZA
dc.source.urihttp://pubs.acs.org/journal/bichaw
dc.titleThe mechanism of beta-hematin formation in acetate solution. Parallels between hemozoin formation and biomineralization processesen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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