Changes in hydrolytic enzyme activities in armadillos infected with Mycobacterium leprae

The activities of hydrolytic enzymes in various organs of armadillos infected with Mycobacterium leprae were compared with those in normal armadillos. Except for aspartate aminopeptidase and esterase, the levels of the other enzymes in liver, spleen and inguinal lymph nodes were significantly higher in armadillos infected with M. leprae compared with those in non-infected ones. These enzymes levels were at a maximum when the animals were sacrificed 22 to 30 months post-inoculation, a period when the bacterial load in the animals had also reached a maximum. Animals infected with M. leprae but not showing any signs of disseminated infection behaved similar to those in the non-infected group. The observed changes in enzymatic activities were not due to bacterial enzymes and so can be related to tissue damage caused by M. leprae.     

Effect of polyols on the thermostability of pullulan-hydrolysing activity from Sclerotium rolfsii

Summary The influence of various polyols on the thermostability of pullulan-hydrolysing activity fromSclerotium rolfsii was studied. The half-life of the enzyme activity at 60°C was determined to be of the order of 30 min. In the presence of xylitol and sorbitol (3 M or more) there was a significant enhancement in the thermostability of the enzyme with retention of 100% activity after incubation for 7 h at 60°C. However, ethylene glycol and glycerol were found to have no protective effect. The stabilizing efficiency was found to be dependent on the concentration of the polyhydric alcohol used and the number of OH-groups present per molecule.     

Hydroxylamine inhibition of the nitrate reductase complex from Amaranthus

Nitrate reductase from Amaranthus viridis is similar to nitrate reductase from other plant sources. NH₂OH inhibits nitrate reduction from NADH by the nitrate reductase complex, but it does not inhibit either the NADH-dehydrogenase activity or nitrate reduction from reduced flavin mononucleotides. The inhibition observed was non-competitive with nitrate when the enzyme was pre-incubated with NH₂OH and NADH, and competitive with nitrate without pre-incubation. The K_i values for NH₂OH were 5 μM and 30 μM with or without pre-incubation respectively.     

The synthesis of 2,1′-anhydro-,2,1′:3,6-dianhydro-, and 2,1′:3,6: 3′,6′-trianhydro-sucrose

1′-O-Mesyl-6,6′-di-O-tritylsucrose and the corresponding 1′-O-tosyl derivative were prepared from 6,6′-di-O-tritylsucrose by selective sulphonylation. Both sulphonates underwent intramolecular cyclisation reactions, to give 2,1′-anhydrosucrose in high yields rather than the isomeric 1′,4′-anhydride. Sequential benzoylation, detritylation, and mesylation of the 2,1′-anhydride afforded 2,1′-anhydro-6,6′-di-O-mesylsucrose tetrabenzoate which, in the presence of base, gave 2,1′:3,6:3′,6′-trianhydrosucrose that was not identical with the product previously claimed to have this structure. Several derivatives of 2,1′-anhydrosucrose were prepared possessing different functional groups at either the 6,6′- or 4,6′-positions. Dimolar mesitylene-sulphonylation of 3,3′,4′6′-tetra-O-acetylsucrose gave the 6,1′-disulphonate, which, in the presence of alkali, gave 2,1′:3,6-dianhydrosucrose, which was transformed into the 2,1′:3,6:3′,6′-trianhydride by sequential bromination at C-6′ (carbon tetrabromide-triphenylphosphine) and base-catalysed cyclisation. Treatment of 3,3′,4′,6′-tetra-O-benzoylsucrose with sulphuryl chloride furnished the 4,6,1′-trichloro derivative, which, on alkaline hydrolysis, was converted into 2,1′:3,6-dianhydro-4-chloro-4-deoxy-galacto-sucrose.     

The novel tungsten-iron-sulfur protein of the hyperthermophilic archaebacterium, Pyrococcus furiosus, is an aldehyde ferredoxin oxidoreductase. Evidence for its participation in a unique glycolytic pathway

The anaerobic archaebacterium, Pyrococcus furiosus, grows optimally at 100 degrees C by a fermentative-type metabolism in which H2, CO2, and organic acids are end products. The growth of this organism is stimulated by tungsten, and, from it, a novel, red-colored, tungsten-iron-sulfur protein, abbreviated RTP, has been purified (Mukund, S., and Adams, M. W. W. (1990) J. Biol. Chem. 265, 11508-11516). RTP (Mr approximately 85,000) contained approximately 1W, 7Fe, and 5 acid-labile sulfide atoms/molecule and exhibited unique EPR properties. The physiological function of the protein, however, was unknown. We show here that RTP is an inactive form of an aldehyde ferredoxin oxidoreductase (AOR). The active enzyme was obtained by rapid purification under anaerobic conditions using buffers containing dithiothreitol and glycerol. AOR catalyzed the oxidation of a range of aliphatic aldehydes with an optimum temperature for activity above 90 degrees C, but it did not oxidize glucose or glyceraldehyde 3-phosphate, nor reduce NAD(P), and its activity was independent of CoA. The active (AOR) and inactive (RTP) forms of the enzyme were indistinguishable in their contents of metals and acid-labile sulfide and in their EPR properties. The latter are though to originate from two nonidentical and spin-coupled iron-sulfur clusters, whereas the tungsten in this enzyme, which was not detectable by EPR, appears to be present as a novel pterin cofactor. Inhibition and activation studies indicated that AOR contains a catalytically essential W-SH group that is not present in RTP, the inactive form. AOR is a new type of aldehyde-oxidizing enzyme and is the first aldehyde oxidoreductase to be purified from an archaebacterium or a nonactogenic anaerobic bacterium. Its physiological role in P. furiosus is proposed as the oxidation of glyceraldehyde to glycerate in a unique, partially nonphosphorylated, glycolytic pathway that generates acetyl-CoA from glucose without the participation of nicotinamide nucleotides.     

Metal Chelates as Fungicides

A remarkable improvement in the emulsifying properties of proteins was observed in mixtures of serum albumin-dextran sulfate, lysozyme-dextran sulfate, serum albumin-chondroitin sulfate, α-lactalbumin-chondroitin sulfate and lysozyme-chondroitin sulfate. The emulsifying properties of these protein-polysaccharide complexes were affected by the molecular size of the polysaccharide and by such conditions as the presence of salt, acidic or alkaline pH, and heating. On the other hand, the emulsifying properties of ovalbumin-dextran hybrids prepared by covalent attachment were more enhanced in alkaline pH or by heating. The molecular size of the ovalbumin-dextran hybrids greatly affected the emulsifying properties.     

Conservation,propagation, and redistribution (CPR) of Hill’s thistle: paradigm for plant species at risk

Cryopreservation is a valuable tool that could potentially create an alternate plant preservation strategy for species at risk such as Hill’s thistle. The present study is focused on a successful paradigm involving conservation, propagation and redistribution (CPR), emaphasizing the usefulness of cryopreservation techniques for plant conservation using Hill’s thistle (Cirsium hillii. (Canby) Fernald). A cryopreservation protocol was established using the droplet-vitrification method for 5-week-old shoot tips of in vitro grown cultures. More than 90% of shoot tips showed regrowth and nearly all regenerated plants were able to survive in the greenhouse. The survival, growth, and development of plants from cryopreserved shoot buds and their performance in field conditions were all comparable or better than the plants from non-cryopreserved buds. Reintroduced plants flowered following overwintering and the magnitude of flowering was site dependent with ca. 80% flowering observed in one site. The site dependent flowering patterns were assessed using phytohormone profiling and compared to herbivory, a common biotic stressor of these plants. Lower tryptophan concentrations led to higher flowering except in alvars, where the limestone resisted root penetration resulting in poor flowering. The presence of tryptamine in the greenhouse acclimatized or alvar field leaves suggested the preparedness of the plants for herbivory/grazing. Serotonin and melatonin concentrations were lower in flowering plants and in sites where the biotic/abiotic stress was minimal. This study provides evidence of the effectiveness of the CPR model in species recovery programs for endangered species. Physiological characterization of plants developed from cryopreserved tissues can be useful for fundamental and applied research in stress adaptation and reproductive biology of plants.

     

RUNX1T1, a potential prognostic marker in breast cancer,is co-ordinately expressed with ERα, and regulated by estrogen receptor signalling in breast cancer cells

Molecular Biology Reports - RUNX1T1 is extensively studied in the context of AML1-RUNX1T1 fusion protein in acute myeloid leukemia. Little is known about the function of RUNX1T1 itself, although...     

Picturing beach erosion and deposition trends using PSInSAR: an example from the non-barred southern west coast of India

Coastal dynamics can rapidly alter beach morphology. In some places, such as the non-barred southern west coast of India, studying changes to beach morphology is a relatively arduous task. Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR), a remote sensing technique that utilizes stacks of radar images for accurate long-term monitoring of ground features, allows for detailed observations of coastal morphodynamics. Twenty-two single look complex (SLC) synthetic aperture radar (SAR) Sentinel-1A images, acquired from 4 March 2016 to 3 June 2017, are used to monitor geomorphological processes such as coastal erosion and deposition. Ground deformation measurements from PSInSAR processing shows the coast stretching?~?70 km between Thaickal and Munambam is highly dynamic, characterized by phases of erosion and deposition. The highest negative displacement of ? 24.9 mm at Thaickal versus the?+?7.6 mm at Chellanam in the north show the co-existing milieus of erosion and deposition. PSInSAR results concur with corresponding Google Earth images. In addition, beach sediment texture and scanning electron microscope grain micro-texture in the beach segment further corroborate temporal phases of erosion and deposition. Two locations are identified as typical erosional sites, while one location typified deposition. Erosion and deposition or rebuilding of beaches, usually correspond respectively with the onset and offset of SW monsoon wave climate in the Arabian Sea. When zones of deposition are mainly located in the proximity of river and/or lake inlets, stretches characterized by erosion are distal to inlets. Linear regression analyses of displacement–time series plots were used to identify general erosion or depositional regimes along beach segments. Results from this study illustrate how PSInSAR is a capable and reliable processing tool for monitoring temporal phases of coastal morpho-dynamics.