Crystal structure of the secreted protein HP1454 from the human pathogen Helicobacter pylori

2014 ◽  
Vol 82 (10) ◽  
pp. 2868-2873 ◽  
Author(s):  
Sandra Quarantini ◽  
Laura Cendron ◽  
Giuseppe Zanotti
2016 ◽  
Vol 194 (2) ◽  
pp. 147-155 ◽  
Author(s):  
Ivana Pulić ◽  
Laura Cendron ◽  
Marco Salamina ◽  
Patrizia Polverino de Laureto ◽  
Dubravka Matković-Čalogović ◽  
...  

2011 ◽  
Vol 79 (5) ◽  
pp. 1678-1681 ◽  
Author(s):  
Gianluca Cioci ◽  
Laurent Terradot ◽  
Cyril Dian ◽  
Christoph Mueller-Dieckmann ◽  
Gordon Leonard

2007 ◽  
Vol 14 (4) ◽  
pp. 442-450 ◽  
Author(s):  
Chandrabali Ghose ◽  
Guillermo I. Perez-Perez ◽  
Victor J. Torres ◽  
Marialuisa Crosatti ◽  
Abraham Nomura ◽  
...  

ABSTRACT The Helicobacter pylori vacA gene encodes a secreted protein (VacA) that alters the function of gastric epithelial cells and T lymphocytes. H. pylori strains containing particular vacA alleles are associated with differential risk of disease. Because the VacA midregion may exist as one of two major types, m1 or m2, serologic responses may potentially be used to differentiate between patients colonized with vacA m1- or vacA m2-positive H. pylori strains. In this study, we examined the utility of specific antigens from the m regions of VacA as allele-specific diagnostic antigens. We report that serological responses to P44M1, an H. pylori m1-specific antigen, are observed predominantly in patients colonized with m1-positive strains, whereas responses to VacA m2 antigens, P48M2 and P55M2, are observed in patients colonized with either m1- or m2-positive strains. In an Asian-American population, serologic responses to VacA m region-specific antigens were not able to predict the risk of development of gastric cancer.


2018 ◽  
Vol 19 (10) ◽  
pp. 3273 ◽  
Author(s):  
Cindy Ulloa-Guerrero ◽  
Maria Delgado ◽  
Carlos Jaramillo

Helicobacter pylori cytotoxin-associated gene A protein (CagA) has been associated with the increase in virulence and risk of cancer. It has been demonstrated that CagA’s translocation is dependent on its interaction with phosphatidylserine. We evaluated the variability of the N-terminal CagA in 127 sequences reported in NCBI, by referring to molecular interaction forces with the phosphatidylserine and the docking of three mutations chosen from variations in specific positions. The major sites of conservation of the residues involved in CagA–Phosphatidylserine interaction were 617, 621 and 626 which had no amino acid variation. Position 636 had the lowest conservation score; mutations in this position were evaluated to observe the differences in intermolecular forces for the CagA–Phosphatidylserine complex. We evaluated the docking of three mutations: K636A, K636R and K636N. The crystal and mutation models presented a ΔG of −8.919907, −8.665261, −8.701923, −8.515097 Kcal/mol, respectively, while mutations K636A, K636R, K636N and the crystal structure presented 0, 3, 4 and 1 H-bonds, respectively. Likewise, the bulk effect of the ΔG and amount of H-bonds was estimated in all of the docking models. The type of mutation affected both the ΔG ( χ 2 ( 1 ) = 93.82 , p-value < 2.2 × 10 − 16 ) and the H-bonds ( χ 2 ( 1 ) = 91.93 , p-value < 2.2 × 10 − 16 ). Overall, 76.9% of the strains that exhibit the K636N mutation produced a severe pathology. The average H-bond count diminished when comparing the mutations with the crystal structure of all the docking models, which means that other molecular forces are involved in the CagA–Phosphatidylserine complex interaction.


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