Comparison of Proteome Components of Helicobacter pylori Before and After Mouse Passage

The mouse model is alleged to be a useful tool for understanding of pathophysiological roles of Helicobacter pylori in the development of gastric disorders. However, it has been observed that H. pylori strains significantly differed in their fitness in mice and even mouse strains differed in their susceptibilities to a H. pylori strain. Bacterial components of H. pylori which could affect on its fitness in mice have to be elucidated for the establishment of the mouse model for H. pylori infections. In the comparison of colonization ability between two H. pylori Korean isolates, 51 (isolated from a patient with duodenal ulcer) and 52 (isolated from a patient with gastric cancer), 52 could colonize better than 51 on the gastric mucosa of mouse. Proteome components of H. pylori 52, as a good colonizer and H. pylori 51, as a poor one were quantitatively compared each other. Five bacterial proteins including catalase, urease subunit alpha/beta, enolase and ferritin, were up-regulated in 52. In addition, the respective proteome components of the two strains were also compared with their mouse-passaged homologous strains. Seven and five proteins, which included catalase, flagellin A/B in common, were up-regulated in mouse-adapted 51 and 52, respectively. Among the fourteen identified proteins, urease subunit alpha/beta, flagellin A/B, catalase, ferritin, superoxide dismutase and neutrophil-activation protein have been previously known to be necessary to gastric colonization of H. pylori in animal models. The other up-regulated proteins including enolase, elongation factor Tu and fructose-bisphosphate aldolase have been reported to be associated with acid tolerance of H. pylori. These data provide confirmatory evidence for the importance of those proteins in the development of H. pylori-associated gastric disorders.

IgG and IgG2 antibodies from cattle naturally infected with Anaplasma marginale recognize the recombinant vaccine candidate antigens VirB9, VirB10, and elongation factor-Tu

Anaplasma marginale is an important vector-borne rickettsia of ruminants in tropical and subtropical regions of the world. Immunization with purified outer membranes of this organism induces protection against acute anaplasmosis. Previous studies, with proteomic and genomic approach identified 21 proteins within the outer membrane immunogen in addition to previously characterized major surface protein1a-5 (MSP1a-5). Among the newly described proteins were VirB9, VirB10, and elongation factor-Tu (EF-Tu). VirB9, VirB10 are considered part of the type IV secretion system (TFSS), which mediates secretion or cell-to-cell transfer of macromolecules, proteins, or DNA-protein complexes in Gram-negative bacteria. EF-Tu can be located in the bacterial surface, mediating bacterial attachment to host cells, or in the bacterial cytoplasm for protein synthesis. However, the roles of VirB9, VirB10, and TFSS in A. marginale have not been defined. VirB9, VirB10, and EF-Tu have not been explored as vaccine antigens. In this study, we demonstrate that sera of cattle infected with A. marginale, with homologous or heterologous isolates recognize recombinant VirB9, VirB10, and EF-Tu. IgG2 from naturally infected cattle also reacts with these proteins. Recognition of epitopes by total IgG and by IgG2 from infected cattle with A. marginale support the inclusion of these proteins in recombinant vaccines against this rickettsia.

Comparison of Protein Expression in Normal Myometrium and Uterine Leiomyoma Using Two-Dimensional Gel Electrophoresis in Korean Women / 대한산부인과학회잡지

OBJECTIVE: Comparison of protein expression by two-dimensional gel electrophoresis (2-DE) in normal myometrium and uterine leiomyoma in Korean women. METHODS: Normal myometrium and uterine leiomyoma tissues were solubilized with 2-DE buffer and the first dimension of PROTEAN IEF CELL, isoelectric focusing (IEF), was performed using pH4-8 linear IPG strips of 17 cm. And then running 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS- PAGE) and sliver stain. Scanned image analyzed using PDQuest 2-D softwareTM. Protein spot spectrum was identified by assisted laser desorption/ionization-time of fighting (MALDI-TOF) and the protein mass spectrums identification were performed by searching protein databases of Swiss-prot/TrEMBL, Mascot and MS-FIT. RESULTS: In this study, we found 17 up-regulated proteins (phosphate carrier protein, 60 kDa heat shock protein, acidic calcium-independent, glutathione transferase omega, chloride intracellular channel 4, Ras-related protein Rab-11B, phosphatidylinositol transfer protein alpha isoform, type II keratin subunit protein, Cofilin 2 isoform 1, transgelin, ATP carrier protein, alpha-catenin homolog, parkinson disease 2, apo-cellular retinoic acid binding protein II, osteoglycin preproprotein, proteasome activator subunit 1 isoform, Unnamed protein) and 7 down-regulated proteins (Serum amyloid P component, annexin IV, alpha 1 actin precursor, hypoxanthine-guanine phosphoribosyltransferase, tumor necrosis factor receptor superfamily member EDAR precursor, peroxiredoxin 2, translation elongation factor EF-Tu precursor) between myometrium and leiomyoma. CONCLUSION: 2-DE offer total protein expression between normal myometrium and uterine leiomyoma, and searching of differently expressed protein for the diagnostic markers of leiomyoma.

Identification of the elongation factor Tu binding site on 70S E. coli ribosomes by chemical crosslinking.

Elongation factor Tu (EF-Tu), in the presence of Phe-tRNA, GMPPCP, and Poly (U), binds to 70S ribosomes at the recognition (R) site. In order to identify the ribosomal proteins adjacent to the EF-Tu occupying the R site, EF-Tu:Phe-tRNA:GMPPCP:ribosome complexes were crosslinked by modification with 2-iminothiolane and mild oxidation to form disulfide bridges between neighbouring proteins whose endogenous or introduced SH groups were appropriately located. The binding of Phe-tRNA to the ribosome was shown to be largely dependent on the presence of Poly(U). The total protein from the complexes was extracted and separated by two-dimensional gel electrophoresis by non-equilibrium pH gradient electrophoresis (NEpHGE) in the first dimension, followed by gradient SDS gel electrophoresis in the second dimension. Comparison of control samples crosslinked without Poly(U) to those crosslinked with Poly(U) present showed a single crosslinked complex in the region of the gel near EF-Tu. No cross-links in the vicinity of EF-Tu were visible in the absence of Poly(U). The crosslinked proteins in this region were recovered by electroelution, radiolabeled and their identity was confirmed by 2D gel electrophoresis and immunoblot analyses. Two major 50S ribosomal proteins, L7/L12 and L10 were found to be covalently linked to EF-Tu. The isolated crosslinked complex did not contain any protein from the 30S subunit. These results demonstrate that L7/L12 and L10 are the major, if not only, ribosomal protein cross-links to EF-Tu in the R site. In contrast to previous crosslinking results obtained by others, our results define a unique location for the EF-Tu binding site, one compatible with functional data and near that of the EF-G binding site on the ribosome.