Search

The crystal structures of BB2672 and SPO0826 were determined to resolutions of 1.7 and 2.1 Å by single-wavelength anomalous dispersion and multiple-wavelength anomalous dispersion, respectively, using the semi-automated high-throughput pipeline of the Joint Center for Structural Genomics (JCSG) as part of the NIGMS Protein Structure Initiative (PSI). These proteins are the first structural representatives of the PF06684 (DUF1185) Pfam family. Structural analysis revealed that both structures adopt a variant of the Bacillus chorismate mutase fold (BCM). The biological unit of both proteins is a hexamer and analysis of homologs indicates that the oligomer interface residues are highly conserved. The conformation of the critical regions for oligomerization appears to be dependent on pH or salt concentration, suggesting that this protein might be subject to environmental regulation. Structural similarities to BCM and genome-context analysis suggest a function in amino-acid synthesis. [ABSTRACT FROM AUTHOR]

Ferritin, with the primary function of iron storage, is a nearly ubiquitous protein found in most living organisms. Our recent investigations suggest that ferritin can assemble nanoparticles. So we use ferritin as a novel type of delivery vehicle for recombinant epitope vaccines. And, we found that ferritin form nonnative aggregates depended sensitively on NaCl concentrations. Here, we report that ferritin is an ion-sensitive protein and has the attribute of salt-dependent aggregation. Our results indicate that recombinant ferritin can be released as a soluble form from Escherichia coli at low NaCl concentrations (≤50 mmol/L). Moreover, this result affords us to confirm a proper self-assembling solution for soluble ferritin or other ferritin-based fusion proteins to assemble nanoparticles. [ABSTRACT FROM AUTHOR]

Background: Aquagenic urticaria is a rare but well-known form of physical urticaria mainly affecting young women. It is characterised by the appearance of erythematous and pruritic plaques a few minutes after initial contact with water and irrespective of temperature. The physiopathology of this condition remains poorly understood. Herein, we report a case of localised aquagenic urticaria occurring solely on contact with seawater., Patients and Methods: A 32-year-old woman reported onset of erythematous and pruritic plaques, confined to the neck and lower part of the face, several minutes after the start of bathing in seawater. Skin tests were carried out by applying wet compresses soaked in seawater (37°C for 30 min) to the areas in which the skin reaction usually occurred. A control test using a compress soaked in fresh water was carried out under identical conditions. An urticaria reaction was noted in the areas in contact with seawater, but no reaction was seen in the areas coming into contact with fresh water. Antihistamines taken on the days of bathing proved ineffective., Discussion: A number of similar cases have been reported in the literature, enabling the characterisation of this particular form of aquagenic urticaria and allowing its principal characteristics to be defined. It appears to be dependent solely on the salt content of the water. It is reported by young women while bathing in seawater. The urticaria plaques show a predilection for the neck and lower part of the face, as in our case, as well as the shoulders on occasion. The efficacy of antihistamines is inconsistent. The prevalence of this as yet poorly known entity is doubtless underreported., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)