Fig. 5
From: Citrullination mediated by PPAD constrains biofilm formation in P. gingivalis strain 381
381 citrullinates gingipain-derived adhesin proteins. a 381 and Δ8820 cell lysates were analyzed by mass spectrometry to identify citrulline residues in 381. Mass spectrometry predicted a citrulline residue within adhesin domain Rgp27 of gingipain RgpA and within adhesin domain Kgp39 of gingipain Kgp (red stars). b, c Recombinant Rgp27 and Kgp39 were expressed in E. coli and then used as substrates in the PPAD enzymatic activity assay. 381 was able to citrullinate both b rRgp27 and c rKgp39 in vitro, whereas Δ8820 was unable to citrullinate rRgp27, rKgp39, or BAEE (positive control). Data in b and c are representative of two independent experiments showing similar results (n = 3). Error bars represent the standard deviation of technical replicates. The data were analyzed by ANOVA with Bonferroni post tests. *p < 0.05
