title: Interactions of Porphyromonas gingivalis with oxyhaemoglobin and deoxyhaemoglobin.
abstract: When grown on blood-containing solid media, the anaerobic periodontal pathogen Porphyromonas gingivalis produces a haem pigment, the major component of which is the mu-oxo bishaem of iron protoporphyrin IX [Smalley, Silver, Marsh and Birss (1998) Biochem. J. 331, 681-685]. In this study, mu-oxo bishaem generation by P. gingivalis from oxy- and deoxyhaemoglobin was examined. Bacterial cells were shown to convert oxyhaemoglobin into methaemoglobin, which was degraded progressively, generating a mixture of both monomeric and mu-oxo dimeric iron protoporphyrin IX. The rate of methaemoglobin formation was accelerated in the presence of bacterial cells, but was inhibited by N-ethylmaleimide and tosyl-lysylchloromethylketone. Interaction of cells with deoxyhaemoglobin resulted in formation of an iron(III) haem species (Soret gamma(max), 393 nm), identified as pure mu-oxo bishaem.
authors.affiliation: Unit of Oral Biology, The Edwards Building, Department of Clinical Dental Sciences, University of Liverpool, Daulby Street, Liverpool L69 3GN, U.K. josmall@liverpool.ac.uk
authors.forename: John W
authors.initials: JW
authors.lastname: Smalley
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Birss
authors.forename: Robert
authors.initials: R
authors.lastname: Withnall
authors.forename: Jack
authors.initials: J
authors.lastname: Silver
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D006454:Hemoglobins / Q000378:metabolism*; D006736:Horses; D010108:Oxyhemoglobins / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000378:metabolism*; D011485:Protein Binding; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin