Since most sequenced mycoplasmal genomes carry both P80 proteins and the alignment result showed distinctively different amino acid composition, the two P80 proteins are clearly unrelated but were historically named P80 simply due to their detected molecular weights. MfeM64YM0621 is a LemA protein, this family of proteins was previously reported to have a predicted N-terminal transmembrane helix and an unknown function. Bacterial lipoproteins are often recognized as virulence factors due to its immunogenic properties. CUDC-907 Membrane-localized lipoproteins often play an important role in the interaction between the bacteria and host cells. Not only do they involve in bacterial adhesion and coaggregation, lipoproteins also have been shown to stimulate the release of pro-inflammatory cytokines. In this study, several M. fermentans predicted lipoproteins were identified, including a number of known lipoproteins, from the Triton X- 114 extraction. Using LipoP, 48 total M. fermentans M64 ORFs were predicted to Rapamycin mTOR inhibitor contain type II lipoprotein signal peptides and 38 ORFs contain type I signal peptide. Among the 48 predicted lipoproteins, 21 of them were identified in this study and their N-terminal signal peptide sequences along with possible cleavage sites were summarized in Table 2. Furthermore, the NF-kB activation of Triton X-114 extraction was measured using a Luciferase reporter assay to determine whether such detergent fraction contains potent NF-kB-activating lipoproteins. Our results showed that the proteins in Triton X-114 extraction showed a significant NF-kB activation activity in mouse macrophage cells compared to the aqueous fraction.. By comparing with known mycoplasmal lipoprotein sequences, seven of the 21 identified lipoproteins were similar to previously reported lipoproteins as indicated in Table 2. MfeM64YM0021 is the phase variant surface lipoprotein P29 and its expression was found to mediate the adherence of M. fermentans to host cells. MfeM64YM0281 is distantly similar to the P100 protein in M. hominis where both are encoded by an opp operon. Besides functioning as a peptide-binding domain of an oligopeptide permease system, previous studies showed that P100 mediated adherence of M. hominis to host cells and also served as the major ATPase on the surface of mycoplasmal cells, and by inducing ATP release and hydrolysis, it caused the apoptosis of HeLa cells in vitro. MfeM64YM0330, as previously described, is similar to the surface membrane lipoprotein P80 of M. agalactiae. MfeM64YM0433 is the ortholog of a phosphonate transport system substrate-binding protein, P37. P37 was first sequenced in M. hyorhinis and the protein itself and the bacterium M. hyorhinis have been associated with several kinds of cancers. In 2009, Sippel et al. has resolved the crystal structure of M. hyorhinis P37.