170 research outputs found
Deconstructing the myth of Pasewalk: Why Adolf Hitler’s psychiatric treatment at the end of World War I bears no relevance
Background Even more than 70 years after the end of WW II, questions regarding the personality of dictator Adolf Hitler (1889-1945) remain unresolved. Among them, there is a focus on the problem of his state of mental health, in particular on the possible relevance of the medical treatment he received for a war injury at the military hospital of the small German town of Pasewalk in the last days of WW I. Some authors have come to postulate a profound change of his personality due either to a psychic trauma suffered or a hypnotic therapy he supposedly underwent for curing a hysterical blindness. Objectives The assumptions about Hitler’s war injury which rely on only two significant sources shall be assessed for their validity. Methods Existing historical sources and inferred hypotheses will be discussed in the light of alternative interpretations. Results The mentioned suppositions reveal their highly arbitrary character: neither a hysterical blindness of Hitler’s nor a hypnotic treatment at Pasewalk military hospital can be substantiated. Discussion Given the fact that Hitler’s medical sheet is most likely irrevocably lost, the authors plea for the acceptance of the limitations of historical research, even more so since the occurrences in Pasewalk lack any deeper importance for a historic assessment of Hitler’s personality
Type II secretion: from structure to function
Gram-negative bacteria use the type II secretion system to transport a large number of secreted proteins from the periplasmic space into the extracellular environment. Many of the secreted proteins are major virulence factors in plants and animals. The components of the type II secretion system are located in both the inner and outer membranes where they assemble into a multi-protein, cell-envelope spanning, complex. This review discusses recent progress, particularly newly published structures obtained by X-ray crystallography and electron microscopy that have increased our understanding of how the type II secretion apparatus functions and the role that individual proteins play in this complex system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74575/1/j.1574-6968.2006.00102.x.pd
Synergistic stimulation of EpsE ATP hydrolysis by EpsL and acidic phospholipids
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102053/1/emboj7601481-sup-0001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102053/2/emboj7601481.pd
Biochemical and Structural Characterization of Selective Allosteric Inhibitors of the Plasmodium falciparum Drug Target, Prolyl-tRNA-synthetase
Plasmodium falciparum (<i>Pf</i>) prolyl-tRNA
synthetase (ProRS) is one of the few chemical-genetically validated
drug targets for malaria, yet highly selective inhibitors have not
been described. In this paper, approximately 40,000 compounds were
screened to identify compounds that selectively inhibit <i>Pf</i>ProRS enzyme activity versus Homo sapiens (<i>Hs</i>) ProRS. X-ray crystallography structures were
solved for apo, as well as substrate- and inhibitor-bound forms of <i>Pf</i>ProRS. We identified two new inhibitors of <i>Pf</i>ProRS that bind outside the active site. These two allosteric inhibitors
showed >100 times specificity for <i>Pf</i>ProRS compared
to <i>Hs</i>ProRS, demonstrating this class of compounds
could overcome the toxicity related to <i>Hs</i>ProRS inhibition
by halofuginone and its analogues. Initial medicinal chemistry was
performed on one of the two compounds, guided by the cocrystallography
of the compound with <i>Pf</i>ProRS, and the results can
instruct future medicinal chemistry work to optimize these promising
new leads for drug development against malaria
Glutaminyl-tRNA Synthetase from Pseudomonas aeruginosa: Characterization, structure, and development as a screening platform
Pseudomonas aeruginosa has a high potential for developing resistance to multiple antibiotics. The gene (glnS) encoding glutaminyl-tRNA synthetase (GlnRS) from P. aeruginosa was cloned and the resulting protein characterized. GlnRS was kinetically evaluated and the KM and kcatobs , governing interactions with tRNA, were 1.0 μM and 0.15 s-1 , respectively. The crystal structure of the α2 form of P. aeruginosa GlnRS was solved to 1.9 Å resolution. The amino acid sequence and structure of P. aeruginosa GlnRS were analyzed and compared to that of GlnRS from Escherichia coli. Amino acids that interact with ATP, glutamine, and tRNA are well conserved and structure overlays indicate that both GlnRS proteins conform to a similar three-dimensional structure. GlnRS was developed into a screening platform using scintillation proximity assay technology and used to screen ~2,000 chemical compounds. Three inhibitory compounds were identified and analyzed for enzymatic inhibition as well as minimum inhibitory concentrations against clinically relevant bacterial strains. Two of the compounds, BM02E04 and BM04H03, were selected for further studies. These compounds displayed broad-spectrum antibacterial activity and exhibited moderate inhibitory activity against mutant efflux deficient strains of P. aeruginosa and E. coli. Growth of wild-type strains was unaffected, indicating that efflux was likely responsible for the lack of sensitivity. The global mode of action was determined using time-kill kinetics. BM04H03 did not inhibit the growth of human cell cultures at any concentration and BM02E04 only inhibit cultures at the highest concentration tested (400 μg/ml). In conclusion, GlnRS from P. aeruginosa is shown to have a structure similar to that of E. coli GlnRS and two natural product compounds were identified as inhibitors of P. aeruginosa GlnRS with the potential for utility as lead candidates in antibacterial drug development in a time of increased antibiotic resistance
Structure of fructose bisphosphate aldolase from Bartonella henselae bound to fructose 1,6-bisphosphate
While other aldolases crystallize readily in the apo form, diffraction-quality crystals of B. henselae aldolase could only be obtained in the presence of the native substrate. The quaternary structure is tetrameric, as is typical of aldolases
Aconitate decarboxylase 1 participates in the control of pulmonary Brucella infection in mice
Brucellosis is one of the most widespread bacterial zoonoses worldwide. Here, our aim was to identify the effector mechanisms controlling the early stages of intranasal infection with Brucella in C57BL/6 mice. During the first 48 hours of infection, alveolar macrophages (AMs) are the main cells infected in the lungs. Using RNA sequencing, we identified the aconitate decarboxylase 1 gene ( Acod1 ;also known as Immune responsive gene 1), as one of the genes most upregulated in murine AMs in response to B .melitensis infection at 24 hours post-infection. Upregulation of Acod1 was confirmed by RT-qPCR in lungs infected with B .melitensis and B .abortus .We observed that Acod1 -/- C57BL/6 mice display a higher bacterial load in their lungs than wild-type (wt) mice following B .melitensis or B .abortus infection, demonstrating that Acod1 participates in the control of pulmonary Brucella infection. The ACOD1 enzyme is mostly produced in mitochondria of macrophages, and converts cis-aconitate, a metabolite in the Krebs cycle, into itaconate. Dimethyl itaconate (DMI), a chemically-modified membrane permeable form of itaconate, has a dose-dependent inhibitory effect on Brucella growth in vitro .Interestingly, structural analysis suggests the binding of itaconate into the binding site of B .abortus isocitrate lyase. DMI does not inhibit multiplication of the isocitrate lyase deletion mutant Δ aceA B .abortus in vitro .Finally, we observed that, unlike the wt strain, the Δ aceA B .abortus strain multiplies similarly in wt and Acod1 -/- C57BL/6 mice. These data suggest that bacterial isocitrate lyase might be a target of itaconate in AMs.info:eu-repo/semantics/publishe
BrabA.11339.a: anomalous diffraction and ligand binding guide towards the elucidation of the function of a ‘putative β-lactamase-like protein’ from Brucella melitensis
The structure of a β-lactamase-like protein from B. melitensis was solved independently using two data sets with anomalous signal. Anomalous Fourier maps could confirm the identity of two metal ions in the active site. AMP-bound and GMP-bound structures provide hints to the possible function of the protein
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