3,544 research outputs found
Polyethylene woven fabric reinforced dentures - properties and construction
published_or_final_versio
An Intergrated Approach for Matching Metals and Metallodrugs to Proteins
Keynote Lecture (Abstract)The effect of metals in biology effects is double-edged. Metal ions operate, on one hand, as
cofactors for around 40% enzymes, on the other hand, they also exhibit toxic effects. Some metal
ions, although being not essential, have been widely used in human healthcare as either therapeutic
agents or diagnosis agents. To understand the molecular mechanism of a metallodrug, it is crucial to match metals to proteins at a proteome-wide scale [1,2]. We used an integrated approach consisting of gel electrophoresis and inductively coupled plasma mass spectrometry, LA-ICP-MS, IMAC and bioinformatic approach to identify metal-associated proteins using bismuth antiulcer drug as an example [3,4]. Using continuous-flow gel electrophoresis in combination with ICP-MS, we developed a comprehensive and robust strategy to readily identify metal-associated proteins as well as to quantify the metals for fast metallome/proteome-wide profiling of metal-binding proteins.
At the same time, we have developed a tunable fluorescent method to visualize metalbinding proteins and histidine-rich proteins directly in cells. To match metals to proteins, we also established a bioinformatic method which allows potential metal-binding proteins both sequentially and spaciously to be searched [5-7]. Surprisingly, histidine-rich proteins and motifs(HRMs) are commonly found in proteins. We systematically analyzed the proteomes of 675 prokaryotes including 50 archaea and 625 bacteria for HRMs, and show that HRMs are extensively distributed in prokaryotic proteomes, with the majority (62%) of histidine-rich proteins (HRPs) being involved in metal homeostasis. Importantly, the occurrence of histidine-rich proteins (motifs) in the proteomes of prokaryotes is related to their habitats.published_or_final_versio
Acrylic resin reinforced with high performance polyethylene fiber
Abstract no. 1269published_or_final_versio
Selective binding of Hpnl towards Ni(II) and Bi(III)
Poster-5Histidine-rich protein Hpn and histidine- and glutamine-rich protein Hpn-like (Hpnl) in Helicobacter pylori have been corroborated to be crucial to nickel homeostasis.[1-3] Nickel supply to hydrogenases and ureases might be disrupted owing to the interaction of metallodrugs, such as bismuth antiulcer drugs, with Hpnl, which may subsequently disturb the functions of the essential …postprin
Selective interaction of Hpn-like protein with nickel, zinc and bismuth in vitro and in cells by FRET
Hpn-like (Hpnl) is a unique histidine- and glutamine-rich protein found only in Helicobacter pylori and plays a role on nickel homeostasis.Weconstructed the fluorescent sensor proteins CYHpnl and CYHpnl_1-48 (C-terminal glutamine-rich region truncated) using enhanced cyan and yellow fluorescent proteins (eCFP and eYFP) as the donor–acceptor pair to monitor the interactions of Hpnl with metal ions and to elucidate the role of conserved Glu-rich sequence in Hpnl by fluorescence resonance energy transfer (FRET). CYHpnl and CYHpnl_1-48 exhibited largest responses towards Ni(II) and Zn(II) over other metals studied and the binding of Bi(III) to CYHpnl was observed in the presence of an excess amount of Bi(III) ions (Kd =115±4.8 μM). Moreover, both CYHpnl and CYHpnl_1-48 showed positive FRET responses towards the binding to Ni(II) and Zn(II) in Escherichia coli cells overexpressing CYHpnl and CYHpnl_1-48, whereas a decrease in FRET upon Bi(III)-binding in E. coli cells overexpressing the latter. Our study provides clear evidence on Hpnl binding to nickel in cells, and intracellular interaction of Hpnl with Bi(III) could disrupt the protein function, thus probably contributing to the efficacy of Bi(III) drugs against H. pylori.postprin
Molecular Characterization of an Atypical IncX3 Plasmid pKPC-NY79 Carrying blaKPC-2 in a Klebsiella pneumoniae
The IncX family of plasmids has recently been expanded to include at least four subtypes, IncX1-IncX4. The revised classification provides an opportunity for improving our understanding of the sequence diversity of the IncX plasmids and the resistance genes they carried. We described the complete nucleotide sequence of a novel IncX3 plasmid, pKPC-NY79 (42,447 bp) from a sequence-type 258 Klebsiella pneumoniae strain that was isolated from a patient who was hospitalized in New York, United States. In pKPC-NY79, the plasmid scaffold and genetic load region were highly similar to homologous regions in pIncX-SHV (IncX3, JN247852) and the bla KPC carrying pKpQIL (IncFII k, GU595196), respectively, indicating that it has possibly arisen through recombination of plasmids. The bla KPC-2 gene, as part of a transposon Tn4401a, was found within the genetic load region. The backbone of pKPC-NY79 differs from pIncX-SHV by a deletion involving the gene tandem hns-topB (encoding H-NS protein and topoisomerase III, respectively) and a putative ATPase gene. Unexpectedly, the impact of the hns-topB deletion on host fitness and plasmid stability was found to be small. In conclusion, the findings contribute to a better understanding of the plasmid platforms carrying bla KPC and of variations in the backbone of the IncX3 plasmids. © 2013 Springer Science+Business Media New York.postprin
Successful control of vancomycin-resistant Enterococcus faecium outbreak in a neurosurgical unit at non-endemic region
Vancomycin-resistant enterococci (VRE) have emerged in many parts of the world, but have only
been reported sporadically in Hong Kong. We report an outbreak of vancomycin-resistant
Enterococcus faecium (VREfm) in a neurosurgical unit at a tertiary teaching hospital between 3
March and 3 April 2009 in Hong Kong. During the outbreak investigation, clinical samples from
193 (91.5%) of 211 patients who had stayed in the neurosurgical unit and 506 environmental
samples were screened for VREfm. Besides the index case, another 3 (1.6%) out of 192 patients
were found to be positive for VREfm. Two (0.4%) out of 506 environmental samples were
positive for VREfm. All four clinical and two environmental isolates were found to be clonally
related by pulse-field gel electrophoresis. The risk factors for nosocomial acquisition of VREfm
included advanced age (P¼0.047), presence of nasogastric tubing (P¼0.002) and tracheostomy
(Po0.001), and the use of b-lactam antibiotics (Po0.001) and vancomycin (P¼0.001).
Contrary to other VRE outbreaks in which the spread was rapid, the neurosurgical patients’
immobilization because of coma and mechanical ventilation dependency, and the vigilant
practice of hand hygiene by health-care workers successfully limited the number of secondary
cases despite the delayed recognition of the index case. All patients with VREfm were labeled in
the hospital network information system so that stringent infection control measures with
contact precautions would be carried out once these patients were readmitted to prevent its
spread in our locality.published_or_final_versio
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