Location of the dicyclohexylcarbodiimide-reactive glutamate residue in the bovine heart mitochondrial porin.

The mitochondrial porin or VDAC (Voltage-Dependent Anion Channel), the pore-forming structure responsible for the high permeability of the outer mitochondrial membrane, was found to be one of only three mitochondrial proteins bound by [14C]dicyclohexylcarbodiimide (DCCD) at low dosages (1.5 nmol/mg of mitochondrial porin) (De Pinto, V., Tommasino, M., Benz, R., and Palmieri, F. (1985) Biochim. Biophys. Acta 813, 230-242). Treatment of intact mitochondria with DCCD results in the inhibition of their ability to binding hexokinase (Nakashima, R. A., Mangan, P. S., Colombini, M., and Pedersen, P. L. (1986) Biochemistry 25, 1015-1021). In the present study, mitochondrial porin was purified from [14C]DCCD-labeled mitochondria. The purified labeled porin was treated with the cleavage reagent CNBr and with the endoproteases trypsin and V8 from Staphylococcus aureus and blotted to polyvinylidene difluoride membrane. The transferred peptides were detected with Coomassie Blue dye, excised, and sequenced. The sequences of several labeled and unlabeled peptides were obtained and then overlapped. The region containing the [14C]DCCD radioactivity was limited to 50 amino acid residues and completely sequenced. Covalently incorporated [14C]DCCD was exclusively released at the position corresponding to glutamate 72. The DCCD-reactive residue is located in the 4th of 16 predicted transmembrane amphipathic beta-strands. When the sequence surrounding the DCCD site was compared to those surrounding the DCCD-reactive residue of other membrane proteins, no homology was apparent

Design of Cationic Multi-Walled Carbon Nanotubes as Efficient siRNA Vectors for Lung Cancer Xenograft Eradication

Polo-Like Kinase (PLK1) has been identified as a potential target in cancer gene therapy via chemical or genetic inhibitory approaches. The biomedical applications of chemically functionalized carbon nanotubes (f-CNTs) in cancer therapy have been studied due to their ability to efficiently deliver siRNA intracellularly. In this study, we established the capacity of cationic MWNT-NH3+ to deliver the apoptotic siRNA against PLK1 (siPLK1) in Calu6 tumor xenografts by direct intratumoural injections. A direct comparison with cationic liposomes was made. This study validates the PLK1 gene as a potential target in cancer gene therapy including lung cancer, as demonstrated by the therapeutic efficacy of siPLK1:MWNT-NH3+ complexes and their ability to significantly improve animal survival. Biological analysis of the siPLK1:MWNT-NH3+ treated tumors by RT-PCR and Western blot, in addition to TUNEL staining confirmed the biological functionality of the siRNA intratumourally, suggesting that tumor eradication was due to PLK1 knockdown. Furthermore, by using a fluorescently labelled, non-coding siRNA sequence complexed with MWNT-NH3+, we established for the first time that the improved therapeutic efficacy observed in f-CNT-based siRNA delivery is directly proportional to the enhanced siRNA retention in the solid tumor and subsequent uptake by tumor cells after local administration in vivo

Fluorinated tranylcypromine analogues as inhibitors of lysine-specific demethylase 1 (LSD1, KDM1A)

We report a series of tranylcypromine analogues containing a fluorine in the cyclopropyl ring. A number of compounds with additional m- or p- substitution of the aryl ring were micromolar inhibitors of the LSD1 enzyme. In cellular assays, the compounds inhibited the proliferation of acute myeloid leukemia cell lines. Increased levels of the biomarkers H3K4me2 and CD86 were consistent with LSD1 target engagement

Temporary Labour–Migration System and Long–term Residence Strategies in the United Arab Emirates

© 2019 The Authors. International Migration © 2019 IOM The United Arab Emirates’ migration system, the sponsorship–based kafala system, is defined as a temporary labour–migration regime. Although there are policies making permanent residence unattainable for virtually all migrants, it is still relevant to explore the temporality of migrations in the UAE. The purpose of this study is to investigate developments in migration, migration policies and population trends in the country, including trends that concern the duration of migrants’ stay. We also identify some of the major strategies used by migrants to prolong their sojourn in the UAE. It is maintained that the migrant stock has increased continuously in the last decades and that a large number of migrants devise strategies to continue their residence and remain in the country for years. The authors also identify and discuss migrants’ transition within and in-between regularity and irregularity, and analyse the reasons for utilizing different strategies over time

Performing the Egyptian revolution : origins of collective restraint action in the Midan

This research was supported by a Carnegie Trust for the Universities of Scotland grant.In January/February 2011, the world watched with admiration the Egyptian revolution that toppled President Housni Mubarak. The demonstration in Midan al-Tahrir (Liberation Square in central Cairo), which was the nucleus of the revolution, highlighted a largely spontaneous, civil and peaceful political performance. However, this performance was temporary, contradicting subsequent bloody conflicts in post-revolutionary Egypt. This article examines the socio-political origins of the Midan performance. It argues that the demonstrators exercised collective restraint, which was temporary but necessary, in order to topple Mubarak. Building on Norbert Elias’ civilising process theory and social movements literature, it is argued that the origins of this performance are found in a collective knowledge of regime strategy and narrative, Egyptian socio-political values and existing repertoires of contention. Drawing on primary sources and semi-structured interviews, the article contends that the demonstrators exercised collective restraint to reframe regime narrative and draw public support for the revolution.PostprintPeer reviewe

Geological and Engineering Properties of Granite Rocks from Aqaba Area

Abstract Jordanian granitic rocks (JG) are highly distributed and available in huge quantities in south Jordan, Aqaba area. Granite in south Jordan (JG) is belonging to Aqaba granite complex. This study has been carried out to investigate geological and engineering properties of JG from Aqaba vicinity, south Jordan, in addition to identify and classify the different granitic rocks. 27 random samples of JG were collected from different quarries in three locations from the study area to investigate their characterization. Engineering properties of JG were tested and investigated using ultra sonic velocity test, abrasion test, flexural strength, specific gravity test, and compressive strength test. Engineering tests results show that JG has metal disk abrasion less than 21 mm, flexural strength of 16.9 Mpa, average dry specific gravity of 2.69 and very low absorption while the compressive strength results range between 60 to 90 Mpa. The results show that the engineering characterization of JG is complying with local and international specifications and standards used for classifying the decorative and building granite stones

Molecular Characterization of Rotavirus Gastroenteritis Strains, Iraqi Kurdistan

Of 260 children with acute diarrhea in Erbil, Iraqi Kurdistan, 96 (37%) were infected with rotavirus. Reverse transcription–polymerase chain reaction identified G1, G4, G2, G9, P[8], P[6], and P[4] as the most common genotypes. Eight G/P combinations were found, but P[8]G1 and P[4]G2 accounted for >50% of the strains

Molecular characterization of rotavirus gastroenteritis strains, Iraqi Kurdistan

Of 260 children with acute diarrhea in Erbil, Iraqi Kurdistan, 96 (37%) were infected with rotavirus. Reverse transcription?polymerase chain reaction identified G1, G4, G2, G9, P[8], P[6], and P[4] as the most common genotypes. Eight G/P combinations were found, but P[8]G1 and P[4]G2 accounted for >50% of the strains

The C-Terminal Domain of the Arabinosyltransferase Mycobacterium tuberculosis EmbC Is a Lectin-Like Carbohydrate Binding Module

The D-arabinan-containing polymers arabinogalactan (AG) and lipoarabinomannan (LAM) are essential components of the unique cell envelope of the pathogen Mycobacterium tuberculosis. Biosynthesis of AG and LAM involves a series of membrane-embedded arabinofuranosyl (Araf) transferases whose structures are largely uncharacterised, despite the fact that several of them are pharmacological targets of ethambutol, a frontline drug in tuberculosis therapy. Herein, we present the crystal structure of the C-terminal hydrophilic domain of the ethambutol-sensitive Araf transferase M. tuberculosis EmbC, which is essential for LAM synthesis. The structure of the C-terminal domain of EmbC (EmbCCT) encompasses two sub-domains of different folds, of which subdomain II shows distinct similarity to lectin-like carbohydrate-binding modules (CBM). Co-crystallisation with a cell wall-derived di-arabinoside acceptor analogue and structural comparison with ligand-bound CBMs suggest that EmbCCT contains two separate carbohydrate binding sites, associated with subdomains I and II, respectively. Single-residue substitution of conserved tryptophan residues (Trp868, Trp985) at these respective sites inhibited EmbC-catalysed extension of LAM. The same substitutions differentially abrogated binding of di- and penta-arabinofuranoside acceptor analogues to EmbCCT, linking the loss of activity to compromised acceptor substrate binding, indicating the presence of two separate carbohydrate binding sites, and demonstrating that subdomain II indeed functions as a carbohydrate-binding module. This work provides the first step towards unravelling the structure and function of a GT-C-type glycosyltransferase that is essential in M. tuberculosis. Author Summary Top Tuberculosis (TB), an infectious disease caused by the bacillus Mycobacterium tuberculosis, burdens large swaths of the world population. Treatment of active TB typically requires administration of an antibiotic cocktail over several months that includes the drug ethambutol. This front line compound inhibits a set of arabinosyltransferase enzymes, called EmbA, EmbB and EmbC, which are critical for the synthesis of arabinan, a vital polysaccharide in the pathogen's unique cell envelope. How precisely ethambutol inhibits arabinosyltransferase activity is not clear, in part because structural information of its pharmacological targets has been elusive. Here, we report the high-resolution structure of the C-terminal domain of the ethambutol-target EmbC, a 390-amino acid fragment responsible for acceptor substrate recognition. Combining the X-ray crystallographic analysis with structural comparisons, site-directed mutagenesis, activity and ligand binding assays, we identified two regions in the C-terminal domain of EmbC that are capable of binding acceptor substrate mimics and are critical for activity of the full-length enzyme. Our results begin to define structure-function relationships in a family of structurally uncharacterised membrane-embedded glycosyltransferases, which are an important target for tuberculosis therapy