The periodontal pathogen Porphyromonas gingivalis harnesses the chemistry of the mu-oxo bishaem of iron protoporphyrin IX to protect against hydrogen peroxide

摘要

The major haem component in the black pigment of Porphyromonas gingivalis is the mu-oxo bishaem of iron protoporphyrin IX and formation and cell-surface binding of this haem species is proposed as an extracellular buffer against reactive oxidants [Smalley, J.W. et al. (1998) Biochem. J. 331, 681-685], P. gingivalis cells grown in the presence of the mu-oxo bishaem were protected against H2O2 compared to control cells grown without it. When added to the growth medium, soluble mu-oxo bishaem inactivated H2O2 and supported cell growth, Cells carrying a surface layer of mu-oxo bishaem were less susceptible to peroxidation by H2O2. Cell-surface haems were slowly destroyed during reaction with H2O2 Binding of mu-oxo bishaem by P. gingivalis may aid survival during neutrophil attack through inactivation of hydrogen peroxide, (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. [References: 27]