246 research outputs found
Pcal_1311, an alcohol dehydrogenase homologue from Pyrobaculum calidifontis, displays NADH-dependent high aldehyde reductase activity
No full textGenome sequence of Pyrobaculum calidifontis, a hyperthermophilic archaeon, harbors three open-reading frames annotated as alcohol dehydrogenases. One of them, Pcal_1311, does not display a significantly high homology with any of the characterized alcohol dehydrogenases. Highest homology of 38% was found with the characterized counterpart from Geobacillus stearothermophilus. To examine the biochemical properties of Pcal_1311, we have cloned and functionally expressed the gene in Escherichia coli. Purified recombinant Pcal_1311 catalyzed the NAD(H)-dependent oxidation of various alcohols and reduction of aldehydes, with a marked preference for substrates with functional group at the terminal carbon. Highest activity for the oxidation reaction (3 μmol min−1 mg−1) was found with 1,4-butanediol and for the reduction reaction (150 μmol min−1 mg−1) with glutaraldehyde. Both the oxidation and reduction activities increased with the increase in temperature up to 80 °C. Recombinant Pcal_1311 was highly stable and retained more than 90% activity even after incubation of 180 min at 90 °C. In addition to the thermostabilty, Pcal_1311 was highly stable in the presence of known denaturants including urea and guanidine hydrochloride. The high stability, particularly thermostability, and the NADH-dependent aldehyde reduction activity make Pcal_1311 a unique member in the alcohol dehydrogenase family
FREQUENCY OF ANXIETY AND DEPRESSION AMONG PATIENTS WITH PULMONARY TUBERCULOSIS
No full textDr. Hina Iqbal*, Dr. Muhammad Naeem Akhtar and Dr. Muhammad Nadim Saqi
EFFICACY OF OCTREOTIDE IN UPPER GASTROINTESTINAL BLEEDING DUE TO VIRAL HEPATITIS INDUCED LIVER CIRRHOSIS
No full textDr. Muhammad Nadim Saqib*, Dr. Muhammad Naeem Akhtar, Dr. Imran Saee
Conformational transmission in proinsulin and its derivatives: a study using H/D exchange
No full textBuffalo proinsulin cDNA was isolated, sequenced and shown to differ from that of its bovine counterpart in six nucleotides. However, at the protein level the predicted sequences of the two species are identical. Buffalo M-proinsulin, containing the initiation methionine, was produced in Escherichia coli and purified to give Mr of 8812. Following the replacement of 99% of the exchangeable hydrogen atoms with deuterons a preparation containing 131 D atoms was obtained. Buffer exchange of the latter into a protio medium led to, the immediate release of 109 (±1) D atoms into the medium and the retention of 22 (±1) D atoms in the protein. The slow exchange of these D atoms was studied at 0 °C/pH 2.8. Insulin derived from buffalo proinsulin as well as bovine when deuteriated and buffer exchanged, similarly, gave the retention of 25 (±1) D atoms. The data show that the secondary structure of the insulin core present within buffalo/bovine proinsulin contains 5 (±1) fewer slow exchanging hydrogen atoms than are present in the final hormone. This effect is attributed, predominantly, to the long range influence of the C-peptide, composed of 26 residues, on the insulin core of buffalo proinsulin. In contrast, in the case of human proinsulin, comprising 31 amino acids in the C-peptide, the secondary structure of the insulin core within human proinsulin is closer to that of insulin itself
The reverse gyrase from Pyrobaculum calidifontis, a novel extremely thermophilic DNA topoisomerase endowed with DNA unwinding and annealing activities
No full textReverse gyrase is a DNA topoisomerase specific for hyperthermophilic bacteria and archaea. It catalyzes the peculiar ATP-dependent DNA-positive supercoiling reaction and might be involved in the physiological adaptation to high growth temperature. Reverse gyrase comprises an N-terminal ATPase and a C-terminal topoisomerase domain, which cooperate in enzyme activity, but details of its mechanism of action are still not clear. We present here a functional characterization of PcalRG, a novel reverse gyrase from the archaeon Pyrobaculum calidifontis. PcalRG is the most robust and processive reverse gyrase known to date; it is active over a wide range of conditions, including temperature, ionic strength, and ATP concentration. Moreover, it holds a strong ATP-inhibited DNA cleavage activity. Most important, PcalRG is able to induce ATP-dependent unwinding of synthetic Holliday junctions and ATP-stimulated annealing of unconstrained single-stranded oligonucleotides. Combined DNA unwinding and annealing activities are typical of certain helicases, but until now were shown for no other reverse gyrase. Our results suggest for the first time that a reverse gyrase shares not only structural but also functional features with evolutionary conserved helicase-topoisomerase complexes involved in genome stability
Inventory of ‘slow exchanging’ hydrogen atoms in human proinsulin and its derivatives: observations on the mass spectrometric analysis of deuterio-proteins in D2O
No full textSecondary structure elements of human proinsulin and of its tryptic products were compared by H/D exchange, in a single-pot, using mass spectrometry. Human proinsulin containing an N-terminal methionine, M-proinsulin, was engineered and converted into a perdeuterio derivative, which using an optimized mass spectrometric protocol and manual calculations gave a mass of 9669.6 (± 1) Da showing the replacement, with deuterium of 146.4 from a total of 149 exchangeable hydrogen atoms (83 from amides and 66 from side-chains). Tryptic digestion of the perdeuterio-M-proinsulin, followed by the transfer of the digest from a deuterio- into a protio-medium showed, at the earliest time of analysis, that of the 27 (± 1) D atoms retained in M-proinsulin, 24 (± 1) were found in the insulin nucleus, M-insulin-RR, and 4.2 (± 1) in the C-peptide-KR. A temporal analysis of the fate of D atoms in these species showed that whereas the C-peptide-KR rapidly exchanged its deuterium, losing all by 6 h, the loss of D atoms from M-proinsulin and M-insulin-RR was gradual and in each case, 12 deuterium atoms survived exchange for 72 h. At all time intervals the loss of D atoms from M-proinsulin mirrored that from M-insulin-RR plus the C-peptide-KR, suggesting that the secondary-structure elements of M-proinsulin are largely conserved in its two component parts
Rhagastis olivacea Moore 1872
No full textRhagastis olivacea (Moore, 1872) Plate 3, Fig. 56 Material examined. PAKISTAN, [Azad Jammu and Kashmir,] Rawalakot, 0 7. viii. 2000, Naeem Akhtar. Remarks. This is the first record of this species from Pakistan. Rhagastis olivacea occurs from northeastern Pakistan, through northern India, Nepal, Myanmar, northern Thailand, Laos and northern Vietnam to southern China (Pittaway & Kitching, 2013).Published as part of Rafi, Muhammad Ather, Sultan, Amir, Kitching, Ian J., Pittaway, Anthony R., Markhasiov, Maxim, Khan, Muhammad Rafique & Naz, Falak, 2014, The Hawkmoth Fauna of Pakistan (Lepidoptera: Sphingidae), pp. 393-418 in Zootaxa 3794 (3) on page 408, DOI: 10.11646/zootaxa.3794.3.4, http://zenodo.org/record/23055
Melatonin induces drought stress tolerance by regulating the physiological mechanisms, antioxidant enzymes, and leaf structural modifications in Rosa centifolia L
No full textMelatonin is considered an effective bio-stimulant that is crucial in managing several abiotic stresses including drought. However, its potential mechanisms against drought stress in fragrant roses are not well understood. Here, we aim to investigate the role of melatonin on Rosa centifolia plants cultivated under drought stress (40 % field capacity) and normal irrigation (80 % field capacity). Plant growth traits, gaseous exchange, antioxidants, osmolytes, oxidative stress, and leaf anatomical attributes were measured. All pots were arranged with a completely randomized design with two-factor factorial setup. Foliar application of melatonin was carried out on the next day of drought treatment and was repeated weekly, while normal watering was regarded as control. Drought stress significantly enhanced oxidative stress markers and reduced growth parameters in water-deficit rose plants. However, melatonin spray (100 μM) produced increased plant height (16 %), flower yield (16 %), petal fresh and dry biomass (7 % and 38 %), total chlorophyll (48 %), contents of carotenoid (54 %), and gaseous exchange traits such as stomatal conductance (25 %), photosynthetic rate (91 %), and transpiration rate (3 %), in water-deficient plants. Likewise, the accretion of catalase, superoxide dismutase, soluble protein, proline, and glycine betaine contents was recorded by 22 %, 45 %, 58 %, 7 %, and 6 %, respectively, in drought-stressed plants, due to melatonin treatment. Increment of oxidative stress indicators i.e. malondialdehyde (−37 %) and hydrogen peroxide (−27 %) was diminished by melatonin triggered by drought stress. Furthermore, leaf cortex (51 %), vascular bundle area (76 %), palisade cell area (59 %), and lamina thickness (42 %) were remarkably increased with melatonin foliar sprays in water-deficit plants. The results of this study recommend that melatonin is a protective agent against drought stress and has potential application prospects in the rose-producing regions suffering from water deficiency. Future studies should focus on molecular responses of R. centifolia to drought stress to further develop stress alleviation strategies in floricultural crops
Carbon-based sorbets for heavy metal removal from aqueous solution, discrepancies, and future prospects: a state-of-the-art review
No full textHeavy metal contamination is severely affecting human health and environment. These metals are known to exist naturally but the anthropogenic activities have contributed towards increasing their concentrations beyond permissible limits, which in turn have proved to be hazardous for the human health as well as environment. Various industries release the untreated wastewater containing heavy metals into the open streams, thereby creating a contaminated source affecting negatively on consumers. In order to deal with this, several materials have been researched and proposed as adsorbents to remove these contaminants. Amongst them are carbon-based materials, that have shown to be effective, efficient, and environment-friendly option for heavy metal adsorption from aqueous solutions. The present review thoroughly summarizes the recent developments of carbon-based materials, specifically in terms of their application in heavy metal removal from aqueous solutions. Moreover, it elaborates the adsorption mechanism and compares it with other technologies available for metallic removal. Similarly, various parameters affecting the adsorption using carbon-based materials and their recent regenerative strategies are presented. In the end, numerous shortcomings and discrepancies associated with carbon-based materials are given along with their future prospects that need to be addressed in the upcoming research.Fil: Akhter, Faheem. No especifíca;Fil: Miranda Zoppas, Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Soomro, Mehran. Mehran University Of Engineering & Technology; PakistánFil: Sattar Jatoi, Abdul. Dawood University Of Engineering & Technology; PakistánFil: Noureen, Fozia. No especifíca;Fil: Naeem Akhtar, Muhammad. Beijing Institute Of Technology,; ChinaFil: Mehreen, Faiza. Mehran University Of Engineering & Technology; Pakistá
Plummer-Vinson Syndrome: A Case Report
No full textPlummer-Vinson syndrome (PVS), also termed as sideropenic dysphagia or Paterson-Brown-Kelly syndrome, is an uncommon medical disorder characterised by three things: iron deficiency anaemia, dysphagia, and esophageal web(s), more often seen in middle-aged females. We present a case of a 45-year-old married lady who came to the medical outpatient department at Abbasi Shaheed Hospital with food swallowing difficulty, fatigue, and generalised body weakness for the past 7 months. Her hematological workup revealed microcytic hypochromic anaemia and barium studies showed smooth circumferential narrowing of the cervical esophagus at the level of the C5-C6 vertebrae (post-cricoid esophageal web). PVS was diagnosed. Endoscopic dilatation or balloon dilatation was advised to treat her dysphagia but was refused by the patient. Her iron deficiency anaemia was corrected with an intravenous iron sucrose supplementation. She was encouraged to eat an iron-rich, semi-solid diet. When she came for a follow-up after six weeks of oral iron supplementation, her condition was satisfactory, and dysphagia had improved
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