Reversible redox regulation of specificityof Arg-gingipain B in Porphyromonas gingivalis
Yu-Yen Chen, Christine A Seers, Nada Slakeski, Caroline Moore, Lianyi Zhang, Eric C Reynolds
FEBS LETTERS | ELSEVIER SCIENCE BV | Published : 2013
Arg-gingipain B (RgpB), a major virulence factor secreted by the periodontal pathogen Porphyromonas gingivalis is an Arg-specific cysteine proteinase. By monitoring proteolytic cleavage of a human salivary peptide histatin 5 using MALDI-TOF MS, RgpB purified from P. gingivalis HG66 was found to shift from a dominant Arg-X to dominant Lys-X activity, both in vitro and in vivo, upon reversible cysteine oxidation. Native PAGE analysis revealed the association of novel Lys-X activity with a reversible state change of the oxidized enzyme. The redox-regulated Lys-X activity of RgpB may provide a survival advantage to P. gingivalis against the oxidative host defence.
We acknowledge the technical assistance of Alvin Lo, Rita Paolini, Zhiguang Xiao and Peter Riley. This work was supported by the Oral Health CRC.