Helicobacter Pylori Urease Research Articles

Clodronic Acid has Strong Inhibitory Interactions with the Urease Enzyme of Helicobacter pylori: Computer-aided Design and in vitro Confirmation.

Helicobacter pylori (HP) infection could lead to various gastrointestinal diseases. Urease is the most important virulence factor of HP. It protects the bacterium against gastric acid. Therefore, we aimed to design urease inhibitors as drugs against HP infection. The DrugBank-approved library was assigned with 3D conformations and the structure of the urease was prepared. Using a re-docking strategy, the proper settings were determined for docking by PyRx and GOLD software. Virtual screening was performed to select the best inhibitory drugs based on binding affinity, FitnessScore, and binding orientation to critical amino acids of the active site. The best inhibitory drug was then evaluated by IC50 and the diameter of the zone of inhibition for bacterial growth. The structures of prepared drugs were screened against urease structure using the determined settings. Clodronic acid was determined to be the best-identified drug, due to higher PyRx binding energy, better GOLD FitnessScore, and interaction with critical amino acids of urease. In vitro results were also in line with the computational data. IC50 values of Clodronic acid and Acetohydroxamic Acid (AHA) were 29.78 ± 1.13 and 47.29 ± 2.06 μg/ml, respectively. Diameters of the zones of inhibition were 18 and 15 mm for Clodronic acid and AHA, respectively. Clodronic acid has better HP urease inhibition potential than AHA. Given its approved status, the development of a repurposed drug based on Clodronic acid would require less time and cost. Further, in vivo studies would unveil the efficacy of Clodronic acid as a urease inhibitor.

Synthesis and biological evaluation of triazolones/oxadiazolones as novel urease inhibitors

Urease is the main virulence factor of infectious gastritis and gastric ulcers. Urease inhibitors are regarded as the first choice for the treatment of such diseases. Based on the triazolone/oxadiazolone skeleton, a urea-like fragment being able to specifically bind the urease activity pocket and prevent urea from hydrolysis, we designed and synthesized 45 triazolones/oxadiazolones as urease inhibitors. Eight compounds were proved to show excellent inhibitory activity against Helicobacter pylori urease, being more potency than the clinically used urease inhibitor acetohydroxamic acid. The most active inhibitor with IC50 value of 1.2 μM was over 20-fold higher potent than the positive control. Enzymatic kinetic assays showed that these novel inhibitors reversibly inhibited urease with a mixed competitive mechanism. Molecular dockings provided evidence for the observations in enzyme assays. Furthermore, these novel inhibitors were proved as drug-like compounds with very low cytotoxicity to mammalian cells and favorable water solubility. These results suggested that triazolone and oxadiazolone were promising scaffolds for the design and discovery of novel urease inhibitors, and were expected as good candidates for further drug development.

Epiberberine inhibits Helicobacter pylori and reduces host apoptosis and inflammatory damage by down-regulating urease expression

Ethnopharmacological relevanceWith dramatically increasing antibiotic resistance in Helicobacter pylori (H. pylori), it is urgent to find alternative therapeutic agents. Rhizoma Coptidis is a traditional Chinese medicine for gastrointestinal diseases and shows excellent anti-H. pylori effect. Epiberberine (EPI), as one of the major alkaloids of Rhizoma Coptidis, has been reported to have urease-inhibiting activity, but its scavenging effect on H. pylori and the potential mechanism remain unclear. Aim of the studyTo investigate the inhibitory effect of EPI on H. pylori and explore its multi-action on Helicobacter pylori urease (HPU). Materials and methodsUsing minimum inhibitory concentration (MIC) assay, minimum bactericidal concentration (MBC) assay, growth inhibition kinetics assay, bacterial resistance development, transmission electron microscope (TEM) assay, and animal experiments to investigate the inhibitory effect of EPI on H. pylori in vitro and in vivo. Using the Berthelot method, molecular docking and thermal displacement experiments to verify that EPI inhibits urease activity by interacting with HPU. Using transcriptome data, Real-Time PCR (RT-PCR) experiments to investigate the alterations in the expression of urease subunit ureB gene after EPI treatment. Using MTT cell viability assay, Hoechst 33342 staining method, JC-1 reagent detection method, western blot experiments, and Griess method to investigate the anti-apoptosis and anti-inflammation actions of EPI on gastric epithelial cells (GES-1) induced by HPU. ResultsIn vitro experiments proved that EPI has significant anti-H. pylori activity without drug resistance, induces H. pylori fragmentation and apoptosis. In vivo experiments showed that EPI has a certain clearance effect of H. pylori, and can reduce gastric inflammation caused by H. pylori infection. Transcriptome data, RT-PCR experiments, and other experiments demonstrate that EPI has a triple effect: (1) inhibiting the expression of HPU subunits ureB, (2) directly inhibiting urease activity by interacting with HPU, and (3) inhibiting HPU-induced apoptosis and inflammation in GES-1. ConclusionsEPI is an excellent anti-H. pylori agent and reduces host apoptosis and inflammation by inhibiting the activity of urease and down-regulating the expression of ureB.

Unraveling putative antiulcer phytoconstituents against Helicobacter pylori urease and human H+/K+-ATPase from Jacaranda mimosifolia using UPLC-MS/MS coupled to chemometrics and molecular docking

Globally peptic ulcer disease is a severe public health issue caused by an imbalance between the defensive and aggressive mechanisms. In the current study, the phytochemical components of various organs (leaf, fruit, seed, and bark) of Jacaranda mimosifolia D. Don collected from Egypt at different seasons and geographical locations were investigated. UPLC-MS/MS allows a tentative identification of 53 compounds where flavonoids, quinoids, and triterpenoids represented the major identified classes. Multivariate statistical analysis (principle component analysis (PCA), hierarchical cluster analysis (HCA)-heat map and orthogonal projection to latent structures-discriminate analysis (OPLS-DA), and accompanied coefficient plots) was applied to investigate in-between and within-class discrimination of the different organs of Jacaranda mimosifolia D. Don. The obtained extracts were tested for their inhibitory activities against Helicobacter pylori Urease and human H+/K+-ATPase enzymes. Fruit extract showed the highest inhibitory activity against H. pylori urease. Meanwhile, leaf extract was found to be more potent, against human H+/K+-ATPase. The results of the biological activities were further modeled using Partial Least Squares Regression (PLSR) analysis together with the quantitative data. The optimal number of latent variables was determined with the aid of Variables important for the projection (VIP) plot to remove the uninformative variables. The developed model was validated using root mean square error of calibration (RMSEC), cross-validation (RMSECV) and prediction (RMSEP). PLS model coefficient plots showed that flavonoids as isoquercitrin and rutin were the most contributing metabolites/biomarkers to the detected anti-urease and H+/K+-ATPase activities, respectively. Molecular docking analysis was utilized to gain more insights into the interaction modalities for the top fifteen metabolites obtained from the PLS model with the active sites of urease and H+/K+-ATPase enzymes. In agreement with the model coefficients, isoquercitrin and rutin were ranked as the top hits for the studied enzymes. To validate the results, in vitro inhibitory assays were performed on isoquercitrin and rutin. Potent inhibitory activities were determined against urease and H+/K+-ATPase with IC50 ± SD of 9.10 ± 0.75 µM and 0.61 ± 0.06 µM for isoquercitrin and rutin, respectively.

Identification of (N-aryl-N-arylsulfonyl)aminoacetohydroxamic acids as novel urease inhibitors and the mechanism exploration

Thirty-three (N-aryl-N-arylsulfonyl)aminoacetohydroxamic acids were synthesized in an effort to develop novel urease inhibitors. Among these compounds, 2-(N-(3-nitrophenyl)-N-(4-tert-butylphenylsulfonyl))aminoacetohydroxamic acid (e2) exhibited excellent inhibitory activity against Helicobacter pylori urease with no perceptible cytotoxicity to mammalian cells. Compound e2 showed over 690-fold higher potency than the clinical used urease inhibitor acetohydroxamic acid, reversibly inhibiting urease with a mixed mechanism. Molecular modeling revealed that (N-aryl-N-arylsulfonyl)aminoacetohydroxamic acids may possibly bind Ni ions and two hydrophobic regions with a 'Y'-like shape.

Gossypol from Gossypium spp. Inhibits Helicobacter pylori Clinical Strains and Urease Enzyme Activity: Bioactivity and Safety Assessments

This study investigates the inhibitory activities of gossypol, a natural polyphenolic compound from Gossypium spp., against Helicobacter pylori (HP) clinical strains and a urease enzyme that plays a key role in the pathogenesis of HP. Gossypol was detected to exhibit a bacteriostatic action against all the HP strains tested with minimum inhibitory concentration (MIC) values ranging from 3.51 to 4.14 µg/mL. The activity of HP urease (HPU) was efficiently impeded by gossypol with a 50% inhibitory concentration (IC50) value of 3.3 µM using an Electrospray Ionization–Mass Spectrometry (ESI-MS)-based method. The in vitro cytotoxicity assay showed no significant cytotoxic properties of gossypol against human gastric epithelial cells. Additionally, molecular docking studies were performed to assess the binding mode and the molecular interactions of gossypol with HPU with a binding affinity value of −8.1 kcal/mol compared with an HPU–acetohydroxamic acid (a standard urease inhibitor) docking complex (–6.1 kcal/mol). The overall results reveal that gossypol might help fight against HP infection by two mechanisms of action: inhibition of the growth of HP and inhibition of urease.

Synthesis, structural characterization, and molecular docking studies of bioactive bismuth(III) complexes with substituted hydrazones

Eight new bismuth(III) complexes (1-8) of substituted hydrazones having general formula; [Bi(RCONHNCHC5H4N)Clx] and [Bi(RCONHNCHC9H6N)Clx], where R = C10H7O (1, and 8), C4H3S (2), C6H5O (3, and 6), C7H7(4), C5H4N (5, and 7), x = 2 or 3 have been prepared. The substituted hydrazones (I1-I8) were synthesized by reacting the stoichiometric amounts of the respective hydrazides such as p-toluic hydrazide, 4-hydroxybenzhydrazide, thiophene-2-carboxylic acid hydrazide, 3-hydroxy-2-naphthoic acid hydrazide, Isonicotic acid hydrazide and appropriate aromatic aldehydes like pridine-2-carboxaldehyde and quinoline-2-carboxyaldehyde. These hydrazones (ligands),then complexed to Bi(III) species to yield the target compounds. They were characterized by FTIR, and NMR spectroscopy to find out an explicit evidence about their structural motifs. The X-ray data for (1 & I6) further validate the chemical structures of the synthesized compounds. The molecular geometry for (1) is predominately distorted pentagonal bipyramidal where hepta-coordinated Bi(III) center is attached to the nitrogens of pyridine and of azomethine moieties along with the carbonyl oxygen, two chloro and two oxygens of the (two) DMSO molecules. The bond lengths for Bi(1)-O(1), Bi(1)-N(1) and Bi(1)-N(2) are 2.323(5), 2.539(6), 2.390(5) oA respectively indicating Bi(1)-O(1) as the strongest linkage to the metal center. The H-bonding, present in (1), contributed an extra stability to the structure. The synthesized compounds were initially screened for their possible antimicrobial, alpha-amylase, and protein kinase inhibition, some (1,2,6,8) exhibit significant activity. The experimental results are further endorsed by molecular docking studies against helicobacter pylori urease (1E9Y), epidermal growth factor receptor tyrosine kinase (1M17) and human pancreatic alpha amylase (5U3A) inhibition activity. The significant ligand-receptor interactions, observed at the binding pocket of the selected drug targets, further revealed the enzyme inhibition potential of the compounds and highlighting their possible roles as therapeutic agents in future drug discovery processes.

Novel (thio)barbituric-phenoxy-N-phenylacetamide derivatives as potent urease inhibitors: synthesis, in vitro urease inhibition, and in silico evaluations

A novel series of (thio)barbituric-phenoxy-N-phenylacetamide derivatives 7a-l was synthesized and evaluated against Helicobacter pylori urease. The latter assay revealed that all the synthesized compounds 7a-l (IC50 = 0.69 ± 0.33–2.47 ± 0.23 μM) were significantly more potent than two used standard inhibitors, thiourea (IC50 = 23 ± 0.73 μM) and hydroxyurea (IC50 = 100 ± 1.7 μM). Docking study of the synthesized compounds demonstrated that these compounds as well fitted in the urease active site. Moreover, molecular dynamic study of the most potent compound 7d showed that this compound created important interactions with the active site flap residues, Cys592 and His593. Furthermore, in silico pharmacokinetic study predicted that all the synthesized compounds are drug-like.

Insights into the Design of Inhibitors of the Urease Enzyme - A Major Target for the Treatment of Helicobacter pylori Infections.

Expressed by a variety of plants, fungi and bacteria, the urease enzyme is directly associated with the virulence factor of many bacteria, including Helicobacter pylori, a gram-negative bacterium related to several gastrointestinal diseases and responsible for one of the most frequent bacterial infections throughout the world. The Helicobacter pylori Urease (HPU) is a nickel-dependent metalloenzyme expressed in response to the environmental stress caused by the acidic pH of the stomach. The enzyme promotes the increase of gastric pH through acid neutralization by the products of urea hydrolysis, then critically contributing to the colonization and pathogenesis of the microorganism. At the same time, standard treatments for Helicobacter pylori infections have limitations such as the increasing bacterial resistance to the antibiotics used in the clinical practice. As a strategy for the development of novel treatments, urease inhibitors have proved to be promising, with a wide range of chemical compounds, including natural, synthetic and semisynthetic products to be researched and potentially developed as new drugs. In this context, this review highlights the advances in the field of HPU inhibition, presenting and discussing the basis for the research of new molecules aiming at the identification of more efficient therapeutic entities.

Insight into the inhibitory effects of Zanthoxylum nitidum against Helicobacter pylori urease and jack bean urease: Kinetics and mechanism.

Zanthoxylum nitidum (Roxb.) DC. is a traditional Chinese medicine characterised by anti-inflammatory and anti-Helicobacter pylori, which is widely used to treat H. pylori-induced gastric disease in China. However, the underlying mechanism related to its anti-H. pylori activity remains unclear. Urease plays a crucial role in the colonisation and survival of H. pylori. The root aqueous extract of Z. nitidum against H. pylori urease (HPU) and jack bean urease (JBU) was investigated to illuminate the inhibitory potency, kinetics and potential mechanism. Z. nitidum components were determined by UPLC. The enzyme inhibitory effects of Z. nitidum were examined using modified spectrophotometric Berthelot (phenol-hypochlorite) method. Urease inhibition kinetics were determined by Lineweaver-Burk plots. Sulfhydryl group reagents and Ni2+-binding inhibitors were used in the mechanism study. Moreover, the molecular docking technique was used to investigate the binding conformations of the main compounds of Z. nitidum on Urease. According to UPLC results, the major components of Z. nitidum were magnoflorine, sanguinarine, nitidine chloride, chelerythrine, skimmianine and L-Sesamin. Z. nitidum has higher enzyme inhibitory activity on HPU (IC50=1.29±0.10mg/mL) than on JBU (IC50=2.04±0.27mg/mL). Enzyme inhibitory kinetic analysis revealed that the type of Z. nitidum inhibition against HPU was a slow-binding and mixed-type, whereas a slow-binding and non-competitive type inhibited JBU. Further mechanism study indicated that the active site of sulfhydryl group might be the target of inhibition by Z. nitidum. The molecular docking study indicated that the above six main components of Z. nitidum exhibited stronger affinity to HPU than to JBU through interacting with the key amino acid residues located on the mobile flap or interacting with the active site Ni2+. Results indicated that these components are potential active ingredients directed against urease. Z. nitidum inactivated urease in a concentration-dependent manner through slow-binding inhibition and binding to the urease active site sulfhydryl group. Our investigation might provide experimental evidence for the traditional application of Z. nitidum in the treatment of H. pylori-associated gastric disorders.

Helicobacter pylori urease induces pro-inflammatory effects and differentiation of human endothelial cells: Cellular and molecular mechanism.

Helicobacter pylori urease (HPU) is a key virulence factor that enables bacteria to colonize and survive in the stomach. We early demonstrated that HPU, independent of its catalytic activity, induced inflammatory and angiogenic responses in vivo and directly activated human neutrophils to produce reactive oxygen species (ROS). We have investigated the effects of HPU on endothelial cells, focusing on the signaling mechanism involved. Monolayers of human microvascular endothelial cells (HMEC-1) were stimulated with HPU (up to 10nmol/L): Paracellular permeability was accessed through dextran-FITC passage. NO and ROS production was evaluated using intracellular probes. Proteins or mRNA expressions were detected by Western blotting and fluorescence microscopy or qPCR assays, respectively. Treatment with HPU enhanced paracellular permeability of HMEC-1, preceded by VE-cadherin phosphorylation and its dissociation from cell-cell junctions. This caused profound alterations in actin cytoskeleton dynamics and focal adhesion kinase (FAK) phosphorylation. HPU triggered ROS and nitric oxide (NO) production by endothelial cells. Increased intracellular ROS resulted in nuclear factor kappa B (NF-κB) activation and upregulated expression of cyclooxygenase-2 (COX-2), hemeoxygenase-1 (HO-1), interleukin-1β (IL-1β), and intercellular adhesion molecule-1 (ICAM-1). Higher ICAM-1 and E-selectin expression was associated with increased neutrophil adhesion on HPU-stimulated HMEC monolayers. The effects of HPU on endothelial cells were dependent on ROS production and lipoxygenase pathway activation, being inhibited by esculetin. Additionally, HPU improved vascular endothelial growth factor receptor 2 (VEGFR-2) expression. The data suggest that the pro-inflammatory properties of HPU drive endothelial cell to a ROS-dependent program of differentiation that contributes to the progression of H pylori infection.

Synthesis of Bacterial Urease Flap Region Peptide Equivalents and Detection of Rheumatoid Arthritis Antibodies Using Two Methods

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that leads to cartilage damage, joint destruction and bone erosions. Serological analysis is one of the most important tools for diagnosis of RA. The aims of studies were the synthesis of an amino-acid library of epitope CHHLDKSIKEDVQFADSRI corresponding to the flap region of H. pylori urease and investigation recognition by serum antibodies from one rheumatoid arthritis patient (RAP) and one volunteer blood donor (VBD) tested by two semi-quantitative methods. In this study we compared two immunoblot variants for estimation of antibodies recognizing five synthetic peptides corresponding to the urease flap region sequence from different organisms. One immunoblot variant was a classic dot-blot using HRP-conjugated anti-human antibodies, where the level of bound immunoglobulins was estimated by digitization of color formed by reaction with secondary antibody. The second immunoblot variant was based on fluorescein-conjugated anti human antibodies. Both semi-quantitative methods were effective for evaluation of antibodies, and their advantages and disadvantages are discussed. To identify the amino-acid residues critical for reaction with antibodies, an amino-acid scan of the complete sequence of the flap region from Helicobacter pylori urease (epitope BK-61B) was conducted. Each sub-library (1–19) contained 19 peptides, each with different amino acids (a–w) at defined positions. All components of the library were synthesized using a divergent strategy. Patterns of serological reaction with the peptide library were unique for each serum sample from an RA patient or control blood donor. The amino-acid residues in epitope BK-61B necessary for strong reaction with antibodies and preventing reaction with antibodies were identified.

Identification of novel urease inhibitors: pharmacophore modeling, virtual screening and molecular docking studies

Pharmacophore modeling and atom-based three-dimensional quantitative structure–activity relationship (3D-QSAR) have been developed on N-acylglycino- and hippurohydroxamic acid derivatives, which are known potential inhibitors of urease. This is followed by virtual screening and ADMET (absorption, distribution, metabolism, excretion and toxicity) studies on a large library of known drugs in order to get lead molecules as Helicobacter pylori urease inhibitors. A suitable three-featured pharmacophore model comprising one H-bond acceptor and two H-bond donor features (ADD.10) has been found to be the best QSAR model. An external library of compounds (∼3000 molecules), pre-filtered using Lipinski’s rule of five, has been further screened using the pharmacophore model ADD.10. By analyzing the fitness of the hits with respect to the pharmacophore model and their binding interaction inside the urease active site, four molecules have been predicted to be extremely good urease inhibitors. Two of these have significant potential and should be taken up for further drug-designing process.

WITHDRAWN: Coptisine, an alkaloid from Rhizoma Coptidis, inhibits Helicobacter pylori urease activity by targeting its active site and maturation process

// Cailan Li 1, * , Ping Huang 2, * , Kambo Wong 3 , Yifei Xu 2 , Lihua Tan 1 , Hanbin Chen 4 , Qiang Lu 5 , Chaodan Luo 1 , Chunlai Tam 3 , Lixiang Zhu 2 , Ziren Su 1, 6 and Jianhui Xie 7 1 Guangdong Provincial Key Laboratory of New Drug Development and Research of Chinese Medicine, Mathematical Engineering Academy of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, P. R. China 2 School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, P. R. China 3 School of Life Sciences, Center for Protein Science and Crystallography, The Chinese University of Hong Kong, Hong Kong, P. R. China 4 The First Affiliated Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, P. R. China 5 Key Laboratory of Ministry of Education, Research Center of Chinese Herbal Resources and Engineering, Guangzhou University of Chinese Medicine, Guangzhou, P. R. China 6 Dongguan Mathematical Engineering Academy of Chinese Medicine, Guangzhou University of Chinese Medicine, Dongguan, P. R. China 7 Guangdong Provincial Key Laboratory of Clinical Research on Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, P. R. China * These authors have contributed equally to this work Correspondence to: Ziren Su, email: suziren@gzucm.edu.cn Jianhui Xie, email: xiejianhui888@hotmail.com Keywords: coptisine; Helicobacter pylori urease; sulfhydryl group; nickel ion; UreG Received: May 18, 2017 Accepted: January 01, 2018 Published: January 02, 2018 ABSTRACT In this study, we examined the anti- Helicobactor pylori effects of the main protoberberine-type alkaloids in Rhizoma Coptidis. Coptisine exerted varying antibacterial and bactericidal effects against three standard H. pylori strains and eleven clinical isolates, including four drug-resistant strains, with MICs ranging from 25 to 50 μg/mL and MBCs ranging from 37.5 to 125 μg/mL. Coptisine’s anti- H. pylori effects derived from specific inhibition of urease in vivo . In vitro , coptisine inactivated urease in a concentration-dependent manner through slow-binding inhibition and involved binding to the urease active site sulfhydryl group. Coptisine inhibition of H. pylori urease (HPU) was mixed type, while inhibition of jack bean urease (JBU) was non-competitive. Importantly, coptisine also inhibited HPU by binding to its nickel metallocenter. Besides, Coptisine interfered with urease maturation by inhibiting activity of prototypical urease accessory protein UreG and formation of UreG dimers and by promoting dissociation of nickel from UreG dimers. These findings demonstrate that coptisine inhibits urease activity by targeting its active site and inhibiting its maturation, thereby effectively inhibiting H. pylori . Coptisine may thus be an effective anti- H. pylori agent.

Synthesis, crystal structures, molecular docking and urease inhibition studies of Ni(II) and Cu(II) Schiff base complexes

[Ni(L)2] 1 and [Cu(L)2] 2 [HL = 2-((E)-(2-methoxyphenylimino)methyl)-4,6-dichlorophenol] Schiff base complexes have been successfully synthesized and were characterized by FT-IR, UV–Vis, fluorescence spectroscopy and thermogravimetric analysis. The crystal structures of the two complexes were determined through X-ray crystallography. Its inhibitory activity against Helicobacter pylori urease was evaluated in vitro and showed strong inhibitory activity against H. pylori urease compared with acetohydroxamic acid (IC50 = 42.12 μmolL−1), which is a positive reference. A docking analysis using the AutoDock 4.0 program could explain the inhibitory activity of the complex against urease.

Expression and Antigenic Evaluation of Helicobacter pylori UreB Fragment

Background: Helicobacter pylori is a common cause of chronic infections worldwide. Helicobacter pylori urease is a multimeric enzyme with a molecular weight of 530 kDa, which is collected from two separate subunits of UreA (26.5 kDa) and UreB (61.7 kDa). Objectives: This study aimed to evaluate the antigenic properties of UreB recombinant protein as a vaccine candidate for the infected sera of humans and mice. Methods: In this study, the highly antigenic region of UreB gene (609 bp) was detected, using immunological bioinformatics for epitope mapping, amplified by polymerase chain reaction (PCR). Afterwards, the antigen was cloned, using a pBSK cloning vector and was inserted into a pET-32a expression vector; the target protein was then expressed and purified. Eventually, antigenicity was examined by immunoblotting on the sera of humans infected with H. pylori UreB recombinant protein. Results: The sequencing results of PCR were indicative of UreB gene cloning into the recombinant plasmid. Production of the protein was induced by isopropyl β-D thiogalactopyranoside (IPTG), and the expressed protein was purified via dialysis, using the Ni-NTA kit. In addition, the recombinant protein with a molecular weight of 42 kDa was recognized by antibodies in Western blotting. Conclusions: The evaluation of antibodies was indicative of high antigenic properties for the immunogenic fragment, predicted by immunological bioinformatics. Therefore, UreB recombinant protein might be a proper antigen for the development of vaccines against H. pylori and other diagnostic kits.

Synthesis, crystal structure, and Helicobacter pylori urease inhibition of a dicyanoamide bridged Cu(I/II) complex

A dicyanoamide-bridged polymeric copper(I/II) complex, [CuII(sal)(bipy)CuI(dca)2]n, was prepared by reaction of 5-methylchlorosalicylaldehyde (Hsal), 2,2′-bipyridine (bipy), sodium dicyanoamide (Nadca), and copper perchlorate in methanol. The complex was characterized by elemental analyses, infrared and electronic spectroscopy, and single-crystal X-ray determination. CuII has a square pyramidal coordination, and CuI has triangular coordination. The complex showed high urease inhibitory activity with IC50 value of 0.16 ± 0.23 μM.

Helicobacter pylori infection in Egyptians with Parkinson′s disease: incidence and the effect on motor fluctuation and response to levodopa

Background Gastrointestinal tract infection with Helicobacter pylori (HP) can inhibit levodopa (LD) in Parkinson's disease (PD) patients, leading to motor fluctuation. Objectives The aim of this study was to identify the incidence of HP in PD patients compared with healthy controls and its effect on motor fluctuation, response to treatment, and quality of life. Patients and methods Serum IgG Abs against HP urease were detected using enzyme-linked immunosorbent assay. We compared the incidence of HP infection in PD patients and controls. We compared PD patients with positive HP (PD positive) and PD patients with negative HP infection (PD negative) with regard to clinical features, the Unified PD Rating Scale (UPDRS) scores, Hoehn and Yahr (H and Y) stages, PD Questionnaire for the quality of life (PD-Q39), and PD Nonmotor Symptoms Questionnaire (PD NMSQ). Results Fifty Egyptians with PD were included. Forty-six percent of patients were HP positive compared with 20% in the control group; the difference was statistically significant ( P = 0.043). In PD-positive patients, the total UPDRS and PD-Q39 scores were significantly higher in comparison with PD-negative patients ( P P < 0.001, respectively). The differences were not significant with regard to the total PD NMSQ score and H and Y stages between the two groups of patients. The LD onset period was significantly greater in PD-positive patients by nearly 14 min in comparison with PD-negative patients. There was a significantly prolonged on-duration time in PD-positive patients in comparison with PD-negative patients. Conclusion There is a high incidence of HP infection in PD. HP affects the response to LD and can deteriorate motor manifestations and the quality of life.

A one-pot multicomponent facile synthesis of dihydropyrimidin-2(1H)-thione derivatives using triphenylgermane as a catalyst and its binding pattern validation

A series of substituted dihydropyrimidin-2(1H)-thione derivatives (1–8) have been synthesized and docked against enzymes human topoisomerase II alpha (4FM9) and Helicobacter pylori urease (1E9Y) for binding mode validation.

Synthesis, structures and urease inhibitory activity of cobalt(III) complexes with Schiff bases

A series of new cobalt(III) complexes were prepared. They are [CoL1(py)3]·NO3 (1), [CoL2(bipy)(N3)]·CH3OH (2), [CoL3(HL3)(N3)]·NO3 (3), and [CoL4(MeOH)(N3)] (4), where L1, L2, L3 and L4 are the deprotonated form of N′-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide, N′-(2-hydroxybenzylidene)-3-hydroxylbenzohydrazide, 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol, and N,N′-bis(5-methylsalicylidene)-o-phenylenediamine, respectively, py is pyridine, and bipy is 2,2′-bipyridine. The complexes were characterized by infrared and UV–Vis spectra, and single crystal X-ray diffraction. The Co atoms in the complexes are in octahedral coordination. Complexes 1 and 4 show effective urease inhibitory activities, with IC50 values of 4.27 and 0.35μmolL−1, respectively. Complex 2 has medium activity against urease, with IC50 value of 68.7μmolL−1. While complex 3 has no activity against urease. Molecular docking study of the complexes with Helicobacter pylori urease was performed.