Identification of Proteins Related to Nickel Homeostasis in Helicobater pylori by Immobilized Metal Affinity Chromatography and Two-Dimensional Gel Electrophoresis

Helicobacter pylori (H. pylori) is a widespread human pathogen causing peptic ulcers and chronic gastritis. Maintaining nickel homeostasis is crucial for the establishment of H. pylori infection in humans. We used immobilized-nickel affinity chromatography to isolate Ni-related proteins from H. pylori cell extracts. Two-dimensional gel electrophoresis and mass spectrometry were employed to separate and identify twenty two Ni-interacting proteins in H. pylori. These Ni-interacting proteins can be classified into several general functional categories, including cellular processes (HspA, HspB, TsaA, and NapA), enzymes (Urease, Fumarase, GuaB, Cad, PPase, and DmpI), membrane-associated proteins (OM jhp1427 and HpaA), iron storage protein (Pfr), and hypothetical proteins (HP0271, HP jhp0216, HP jhp0301, HP0721, HP0614, and HP jhp0118). The implication of these proteins in nickel homeostasis is discussed

A Novel Iron Transporter SPD_1590 in Streptococcus pneumoniae Contributing to Bacterial Virulence Properties

Streptococcus pneumoniae, a Gram-positive human pathogen, has evolved three main transporters for iron acquisition from the host: PiaABC, PiuABC, and PitABC. Our previous study had shown that the mRNA and protein levels of SPD_1590 are significantly upregulated in the ΔpiuA/ΔpiaA/ΔpitA triple mutant, suggesting that SPD_1590 might be a novel iron transporter in S. pneumoniae. In the present study, using spd1590-knockout, -complemented, and -overexpressing strains and the purified SPD_1590 protein, we show that SPD_1590 can bind hemin, probably supplementing the function of PiuABC, to provide the iron necessary for the bacterium. Furthermore, the results of iTRAQ quantitative proteomics and cell-infection studies demonstrate that, similarly to other metal-ion uptake proteins, SPD_1590 is important for bacterial virulence properties. Overall, these results provide a better understanding of the biology of this clinically important bacterium

Bacterial Phosphoproteomic Analysis Reveals the Correlation Between Protein Phosphorylation and Bacterial Pathogenicity

AbstractIncreasing evidence shows that protein phosphorylation on serine, threonine and tyrosine residues is a major regulatory post-translational modification in the bacteria. This review focuses on the implications of bacterial phosphoproteome in bacterial pathogenicity and highlights recent development of methods in phosphoproteomics and the connectivity of the phosphorylation networks. Recent technical developments in the high accuracy mass spectrometry have dramatically transformed proteomics and made it possible the characterization of a few exhaustive site-specific bacterial phosphoproteomes. The high abundance of tyrosine phosphorylations in a few bacterial phosphoproteomes suggests their roles in the pathogenicity, especially in the case of pathogen–host interactions; the high abundance of multi-phosphorylation sites in bacterial phosphoprotein is a compensation of the relatively small phosphorylation size and an indicator of the delicate regulation of protein functions

A biochemical and proteomic view of nickel homeostasis and bismuth treatment: identification of bismuth-targetedproteins in Helicobacter pylori and characterization of a nickel-storage protein hpn

abstractpublished_or_final_versionChemistryDoctoralDoctor of Philosoph

High-Efficient Liquid Exfoliation of Boron Nitride Nanosheets Using Aqueous Solution of Alkanolamine

Abstract As one of the simple and efficient routes to access two-dimensional materials, liquid exfoliation has received considerable interest in recent years. Here, we reported on high-efficient liquid exfoliation of hexagonal boron nitride nanosheets (BNNSs) using monoethanolamine (MEA) aqueous solution. The resulting BNNSs were evaluated in terms of the yield and structure characterizations. The results show that the MEA solution can exfoliate BNNSs more efficiently than the currently known solvents and a high yield up to 42% is obtained by ultrasonic exfoliation in MEA-30 wt% H2O solution. Finally, the BNNS-filled epoxy resin with enhanced performance was demonstrated

Efficient removal of aqueous Pb(II) using partially reduced graphene oxide-FeO

Partially reduced graphene oxide-Fe 3 O 4 composite was prepared through in situ co-precipitation and used as an efficient adsorbent for removing Pb(II) from water. The composites were characterized by X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectra, Fourier transformation infrared, Raman spectrometer, N 2 adsorption–desorption, vibrating sample magnetometer, and zeta potential analyses. The impacts of pH, contact time, adsorbent dosage, temperature, and foreign substances on Pb(II) adsorption performance were investigated. The adsorption mechanism, kinetics, and thermodynamics were analyzed. The results indicate that Fe 3 O 4 is homogeneously anchored inside the thin graphene sheets, with a particle size of 15–20 nm, resulting in a very low remanence and coercivity. The composite shows excellent and efficient adsorption performance toward aqueous Pb(II): adsorption equilibrium was reached in 10 min with the adsorption percent and quantity of 95.77% and 373.14 mgċg −1 , respectively, under a condition of pH = 6, adsorbent dosage 250 mgċL −1 , and Pb(II) initial concentration 97.68 mgċL −1 , with the subsequent magnetic separation taking only 10 s. The adsorption performance is dependent on adsorbent dosage. A lower dosage favors a higher adsorption quantity, implying a strong adsorptive potential for partially reduced graphene oxide-Fe 3 O 4 . The adsorption quantity reached 777.28 mgċg −1 , given the dosage 100 mgċL −1 . The adsorption is monolayer chemisorption, the whole process of which is controlled by chemisorption and liquid film diffusion. In terms of thermodynamics, the adsorption is an exothermic and spontaneous process