Original Article
Analysis of virulence factors of Porphyromonas endodontalis based on comparative proteomics technique
Hong Li, Hai Ji, Shanshan Wu, Benxiang Hou
Published 2016-12-09
Cite as Chin J Stomatol, 2016, 51(12): 746-752. DOI: 10.3760/cma.j.issn.1002-0098.2016.12.009
Abstract
ObjectiveTo analyze the protein expression profile and the potential virulence factors of Porphyromonas endodontalis (Pe) via comparison with that of two strains of Porphyromonas gingivalis (Pg) with high and low virulences, respectively.
MethodsWhole cell comparative proteomics of Pe ATCC35406 was examined and compared with that of high virulent strain Pg W83 andlow virulent strain Pg ATCC33277, respectively. Isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano liquid chromatography-tandem mass spectrometry (Nano-LC-MS/MS) were adopted to identify and quantitate the proteins of Pe and two strains of Pg with various virulences by using the methods of isotopically labeled peptides, mass spectrometric detection and bioinformatics analysis. The biological functions of similar proteins expressed by Pe ATCC35406 and two strains of Pg were quantified and analyzed.
ResultsTotally 1 210 proteins were identified while Pe compared with Pg W83. There were 130 proteins (10.74% of the total proteins) expressed similarly, including 89 known functional proteins and 41 proteins of unknown functions. Totally 1 223 proteins were identified when Pe compared with Pg ATCC33277. There were 110 proteins (8.99% of the total proteins) expressed similarly, including 72 known functional proteins and 38 proteins of unknown functions. The similarly expressed proteins in Pe and Pg strains with various virulences mainly focused on catalytic activity and binding function, including recombination activation gene (RagA), lipoprotein, chaperonin Dnak, Clp family proteins (ClpC and ClpX) and various iron-binding proteins. They were involved in metabolism and cellular processes. In addition, the type and number of similar virulence proteins between Pe and high virulence Pg were higher than those between Pe and low virulence Pg.
ConclusionsLipoprotein, oxygen resistance protein, iron binding protein were probably the potential virulence factors of Pe ATCC35406. It was speculated that pathogenicity of Pe was more similar to high virulence Pg than that to low virulence strain.
Key words:
Porphyromonas gingivalis; Porphyromonas endodontalis; Proteomics; Isotope labeling; Mass spectrometry
Contributor Information
Hong Li
Department of Endodontics, School of Stomatology, Capital Medical University, Beijing 100050, China
Hai Ji
Department of Endodontics, School of Stomatology, Capital Medical University, Beijing 100050, China
Shanshan Wu
Department of Endodontics, School of Stomatology, Capital Medical University, Beijing 100050, China
Benxiang Hou
Department of Endodontics, School of Stomatology, Capital Medical University, Beijing 100050, China
