HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Smalley, J. W. Articles by Titler, P. J. Search for Related Content PubMed PubMed Citation Articles by Smalley, J. W. Articles by Titler, P. J. Agricola Articles by Smalley, J. W. Articles by Titler, P. J.

The haem pigment of the oral anaerobes Prevotella nigrescens and Prevotella intermedia is composed of iron(III) protoporphyrin IX in the monomeric form

¹ Department of Clinical Dental Sciences, The University of Liverpool, Liverpool L69 3GN, UK
² School of Chemical and Life Sciences, The University of Greenwich, Chatham Maritime Campus, Pembroke, Chatham ME4 4TB, UK

Correspondence
John W. Smalley
josmall{at}liv.ac.uk

The haem pigment of Porphyromonas gingivalis is composed of µ-oxo bishaem, [Fe(III)PPIX]₂O, but the nature of that generated by Prevotella species has not been established. Mössbauer, Raman and UV-visible spectrophotometry were used to characterize the haem pigment of Prevotella intermedia and Prevotella nigrescens. Mössbauer and Raman spectroscopy revealed the major haem species to be monomeric iron protoporphyrin IX, Fe(III)PPIX.OH (haematin). The terminal growth pH of both species on blood agar was between 5·8 and 6·0, which favours the formation and maintenance of monomeric Fe(III)PPIX.OH. Incubation of Pr. nigrescens and Pr. intermedia with oxyhaemoglobin at pH 6·5 resulted in formation of aquomethaemoglobin which was degraded to generate Fe(III)PPIX.OH which in turn became cell-associated, whilst incubation at pH 7·5 resulted in formation of [Fe(III)PPIX]₂O. It is concluded that both Prevotella species degrade oxyhaemoglobin to form [Fe(III)PPIX]₂O as an intermediate, which is converted to Fe(III)PPIX.OH through a depression in pH. The low pH encourages cell-surface deposition of insoluble Fe(III)PPIX.OH which would act as a barrier against oxygen and reactive oxygen species, and also protect against H₂O₂ through its inherent catalase activity.

This article has been cited by other articles:

				N. S. Soukos, S. Som, A. D. Abernethy, K. Ruggiero, J. Dunham, C. Lee, A. G. Doukas, and J. M. Goodson Phototargeting Oral Black-Pigmented Bacteria Antimicrob. Agents Chemother., April 1, 2005; 49(4): 1391 - 1396. [Abstract] [Full Text] [PDF]