Structural comparison of urease and a GroEL analog from Helicobacter pylori

Austin, John W.; Doig, P.; Stewart, M; Trust, Trevor J.

doi:10.1128/jb.174.22.7470-7473.1992

Cited by 39 publications

(25 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Subcellular localization of HpaA in H. pylori. The subcellular localization of proteins in H. pylori has proved difficult, presumably because of the apparent ease with which proteins that are invariably cytoplasmic in other species may leak out of the Helicobacter cell and become associated with the surface (3,11,51). To tackle this problem, we have recently established a fractionation procedure which correlates the presence of seven separate protein antigens and lipopolysaccharide in the outer membrane fraction with the reactivities of respective monoclonal antibodies with the cell surface (13).…”

Section: Resultsmentioning

confidence: 99%

The putative neuraminyllactose-binding hemagglutinin HpaA of Helicobacter pylori CCUG 17874 is a lipoprotein

O’Toole¹,

Janzon²,

Doig³

et al. 1995

J Bacteriol

Self Cite

View full text Add to dashboard Cite

. 175:674-683, 1993), the gene for which has been cloned and sequenced. On the basis of the hydropathy plot of HpaA and the presence of a potential lipoprotein signal sequence and modification site, and because of the similarities of these features with those of the cell envelope lipoprotein Lpp20 of H. pylori, we examined the possibility that HpaA was also a lipoprotein. Posttranslational processing of the HpaA protein expressed by the cloned gene was sensitive to globomycin, an inhibitor of the lipoprotein-specific signal peptidase II. Antibodies raised to the putative sialic acid-binding region of HpaA failed to bind to the surface of H. pylori cells in immunoelectron microscopy but instead were observed to have labeled the cytoplasm when thin sections were examined. This antibody recognized a 29,000-M r protein in Western blots (immunoblots) of cell extracts of H. pylori and Escherichia coli cells expressing the cloned hpaA gene. Determination of the sequence of hpaA from strain CCUG 17874 indicated significant differences from that determined by Evans and coworkers in the above-mentioned study, including extension of the gene into the open reading frame 3 downstream of hpaA to produce a protein with an M r of 26,414. Localization of HpaA indicated that it was predominantly located in the cytoplasmic fraction of the cell in both E. coli and H. pylori. HpaA was not observed in the sarkosyl-insoluble outer membrane fraction. An isogenic mutant generated by insertional inactivation of hpaA was unaffected in its ability to bind four different human cell lines as well as fixed sections of gastric tissue and had hemagglutination properties identical to those of the wild type. The data collectively suggest that HpaA is a nonessential lipoprotein internal to the H. pylori cell and that it is not involved in adhesion.

show abstract

Section: Resultsmentioning

confidence: 99%

The putative neuraminyllactose-binding hemagglutinin HpaA of Helicobacter pylori CCUG 17874 is a lipoprotein

O’Toole¹,

Janzon²,

Doig³

et al. 1995

J Bacteriol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although the crystalline structure of the HSA crystals used in this study may be different (ammonium sulfate was used as a precipitant instead of PEG), one can clearly appreciate the highly ordered structure of crystalline antigens. In this respect CLPC strikingly resemble polyvalent particulate structures of the hepatitis B surface antigen (33), Helicobacter pylori urease (34), and virus-like particles (VLP) (35). In the VLPs, antigens are genetically fused to the TYA gene, which encodes a particle-forming protein that can self-assemble.…”

Section: Discussionmentioning

confidence: 99%

Cross-linked protein crystals for vaccine delivery

Clair

Shenoy

Jacob

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The progress toward subunit vaccines has been limited by their poor immunogenicity and limited stability. To enhance the immune response, subunit vaccines universally require improved adjuvants and delivery vehicles. In the present paper, we propose the use of cross-linked protein crystals (CLPCs) as antigens. We compare the immunogenicity of CLPCs of human serum albumin with that of soluble protein and conclude that there are marked differences in the immune response to the different forms of human serum albumin. Relative to the soluble protein, crystalline forms induce and sustain over almost a 6-month study a 6-to 10-fold increase in antibody titer for highly cross-linked crystals and an approximately 30-fold increase for lightly cross-linked crystals. We hypothesize that the depot effect, the particulate structure of CLPCs, and highly repetitive nature of protein crystals may play roles in the enhanced production of circulating antibodies. Several features of CLPCs, such as their remarkable stability, purity, biodegradability, and ease of manufacturing, make them highly attractive for vaccine formulations. This work paves the way for a systematic study of protein crystallinity and cross-linking on enhancement of humoral and T cell responses.

show abstract

“…§1734 solely to indicate this fact. lecular mass of 54-62 kDa (16)(17)(18). This protein was identified to be a homolog of the class of heat shock proteins (HSPs), to which Escherichia coli GroEL belongs (16)(17)(18); the gene encoding the 54-kDa protein was designated hspB (19).…”

mentioning

confidence: 99%

“…lecular mass of 54-62 kDa (16)(17)(18). This protein was identified to be a homolog of the class of heat shock proteins (HSPs), to which Escherichia coli GroEL belongs (16)(17)(18); the gene encoding the 54-kDa protein was designated hspB (19). Analysis of the DNA region upstream of hspB revealed a second open reading frame (designated hspA) that encoded a protein with a deduced molecular mass of 13 kDa (19).…”

mentioning

confidence: 99%

The GroES homolog of Helicobacter pylori confers protective immunity against mucosal infection in mice.

Ferrero¹,

Thiberge²,

Kansau³

et al. 1995

Proc. Natl. Acad. Sci. U.S.A.

267

186

View full text Add to dashboard Cite

Helicobacter pylori is an important etiologic agent of gastroduodenal disease. In common with other organisms, H. pylori bacteria express heat shock proteins that share homologies with the GroES-GroEL class of proteins from Escherichia coli. We have assessed the heat shock proteins of H. pylori as potential protective antigens in a murine model of gastric Helicobacter infection. Orogastric immunization of mice with recombinant H. pylori GroES-and GroELlike proteins protected 80% (n = 20) and 70% (n = 10) of animals, respectively, from a challenge dose of 104 Helicobacter felis bacteria (compared to control mice, P = 0.0042 and P = 0.0904, respectively). All mice (n = 19) that were immunized with a dual antigen preparation, consisting of H. pylori GroES-like protein and the B subunit ofH. pylori urease, were protected against infection. This represented a level of protection equivalent to that provided by a sonicated Helicobacter extract (P = 0.955). Antibodies directed against the recombinant H. pylori antigens were predominantly of the IgGl class, suggesting that a type 2 T-helper cell response was involved in protection. This work reports a protein belonging to the GroES class of heat shock proteins that was shown to induce protective immunity. In conclusion, GroES-like and urease B-subunit proteins have been identified as potential components of a future H. pylori subunit vaccine.

show abstract

Structural comparison of urease and a GroEL analog from Helicobacter pylori

Cited by 39 publications

References 18 publications

The putative neuraminyllactose-binding hemagglutinin HpaA of Helicobacter pylori CCUG 17874 is a lipoprotein

The putative neuraminyllactose-binding hemagglutinin HpaA of Helicobacter pylori CCUG 17874 is a lipoprotein

Cross-linked protein crystals for vaccine delivery

The GroES homolog of Helicobacter pylori confers protective immunity against mucosal infection in mice.

Contact Info

Product

Resources

About