Smalley, John W.; Thomas, Michael F.; Birss, Andrew J.; Withnall, Robert and Silver, Jack (2004) A combination of both arginine- and lysine-specific gingipain activity of Porphyromonas gingivalis is necessary for the generation of the m-oxo bishaem-containing pigment from haemoglobin. Biochemical Journal, 379 . pp. 833-840. ISSN 0264-6021
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The black pigment of Porphyromonas gingivalis is composed of the μ-oxo bishaem complex of iron(III) protoporphyrin IX (μ-oxo oligomer, dimeric haem), [Fe(III)PPIX]2O. P. gingivalis W50 and Rgp- and Kgp-gingipain protease-deficient mutants K1A, D7, E8 and W501 (Aduse-Opoku, , Davies, Gallagher, Hashim, Evans, Rangarajan, Slaney and Curtis (2000) Microbiology 146 , 1933-1940) were grown on horse blood agar for 14 days and examined for production of μ-oxo bishaem. The μ-oxo bishaem was detected by UV-visible, Mössbauer and Raman spectroscopy in wild type W50, and in the black-pigmented RgpA-deficient and RgpB-deficient mutants (W501 and D7), whilst no haems were detected in the straw-coloured Kgp-deficient strain K1A. The dark brown pigment of the double RgpA/RgpB knockout mutant (E8) was not composed of μ-oxo bishaem, but of a high-spin monomeric iron(III) protoporphyrin IX species (possibly a haem-albumin complex). In vitro incubation of oxyhaemoglobin with cells of strains W50, and the RgpA- and RgpB-deficient mutants (W501 and D7) resulted in formation of μ-oxo bishaem via methaemoglobin as an intermediate. Whilst the Kgp-deficient strain K1A converted oxyhaemoglobin into methaemoglobin, this was not further degraded into μ-oxo bishaem. The double RgpA/RgpB knockout was also unable to produce μ-oxo bishaem from oxyhaemoglobin, but instead generated a haemoglobin haemichrome. Inhibition of Arg-X protease activity of W50, W501, D7 and K1A with leupeptin under conditions where Lys-X protease activity was unaffected, prevented μ-oxo bishaem production from oxyhaemoglobin, but resulted in formation of a haemoglobin haemichrome. These data show that one or both of RgpA- and RgpB-gingipains, in addition to the lysine-specific gingipain, is necessary for production of the μ-oxo bishaem from haemoglobin by whole cells of P. gingivalis.
|Additional Information:||Published as BJ Immediate Publication 23 January 2004.|
|Uncontrolled Keywords:||Porphyromonas; Lys-gingipain; Arg-gingipain; μ-oxo bishaem; haemoglobin; protease|
|Subjects:||R Medicine > RK Dentistry|
|Departments, Research Centres and Related Units:||Academic Faculties, Institutes and Research Centres > Faculty of Medicine > School of Dental Sciences|
|Publisher's Statement:||The final version of record is available at www.biochemj.org.|
|Deposited On:||07 May 2008 16:57|
|Last Modified:||20 May 2011 18:58|
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