1H NMR-visible mobile lipid domains correlate with cytoplasmic lipid bodies in apoptotic T-lymphoblastoid cells

The presence of nuclear magnetic resonance (NMR)-visible mobile lipid (ML) domains in apoptotic lymphoblasts suggests alterations in neutral lipid metabolism and compartmentation during programmed cell death. The detection of similar ML signals in activated lymphocytes raises questions about common mechanisms of ML formation during apoptosis and upon lymphoblast stimulation. Structure and subcellular localization of ML domains were therefore investigated by NMR, fluorescence and electron microscopy in Jurkat T-lymphoblasts either induced to apoptosis (by anthracyclines or dexamethasone or by serum deprivation) or activated by phorbol myristate acetate (PMA) plus ionomycin. ML contents in drug-treated cells correlated linearly with apoptosis, irrespective of the specific inducer and cell cycle arrest phase (r=0.993, P<0.001). Similar ML levels were measured in drug-induced apoptotic cells (A≈30–40%) and in non-apoptotic PMA/ionomycin-treated lymphoblasts (72 h). Lower ML contents were instead formed in serum-deprived apoptotic cells, with respect to controls. Increases in ML signals were associated, in either apoptotic or activated cells, with the accumulation of cytoplasmic, osmophilic lipid bodies (diameter≤1.0 μm), surrounded by own membrane, possessing intramembrane particles. The results support the hypothesis that ML are formed in the cytoplasm of drug-induced apoptotic cells during an early, ‘biochemically active’ phase of programmed cell death.     

Amino Acid Sequence and Molecular Weight of Native NADP Malate Dehydrogenase from the C(4) Plant Zea mays

N-terminus amino acid analysis of purified corn (Zea mays) NADP malate dehydrogenase showed that the mature protein begins at serine-41 of the preprotein sequence and not threonine-58 as previously concluded; therefore, the transit peptide consists of 40 amino acids. The theoretical molecular weight of the mature subunit protein (392 amino acids) is 42,564, agreeing with an experimental value of about 43,000. The molecular weight of the native unactivated (dark form) and activated (light form) of NADP malate dehydrogenase, determined by analytical ultracentrifugation analysis, was about 84,000, indicating that both forms are dimers. However, conventional and high performance liquid chromatography gel filtration procedures indicated apparent molecular weights of about 110,000 to 120,000 for the unactivated native enzyme and about 143,000 to 150,000 for the active enzyme; in these cases, the molecular weight may be overestimated due to the effect of an unusual molecular conformation on the mobility of the enzyme.     

Adenosine deaminase polymorphism in sardinia

Summary Red blood cell adenosine deaminase and G-6-PD polymorphisms have been studied in the populations of 17 Sardinian villages located at various altitudes. A total of 1615 individuals of both sexes, with age between 7 and 14 years were examined.The negative relationship between Gd^Med gene frequency and altitude was confirmed.Adenosine deaminase polymorphism showed a considerable variability among the villages examined: ADA² frequency ranged from 0.025 to 0.106. The ADA² frequency was negatively related (p< 0.05) with Gd^Med gene frequency.

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Zusammenfassung Die Erythrocyten-Adenosin-Desaminase und Glucose-6-Phosphat-Dehydrogenase-Polymorphismen sind in Stichproben aus der Bevölkerung von 17 Dörfern auf Sardinien untersucht worden. Diese sind in verschiedener Höhe über dem Meer im zentralen Teil der Insel gelegen.Die negative Häufigkeitsbeziehung zwischen der Genfrequenz Gd^Med und der Höhenlage der Dörfer konnte bestätigt werden.Der Adenosin-Desaminase-Polymorphismus zeigt eine beträchtliche Variabilität zwischen den verschiedenen Dorfpopulationen. Die ADA²-Frequenz liegt zwischen 0,025 und 0,106. Die ADA²-Frequenz steht in negativer Beziehung (p< 0,05) zur Gd^Med-Frequenz.

     

Growth ofCandida albicans in a minimal synthetic medium without biotin

Summary Growth ofCandida albicans strain B 311-10 was observed in a minimal synthetic biotin-free medium, using different glucose concentrations, during the first 30 hours of its development at 28 °C. The yeast's growth was observed spectrophotometrically at 675 nm reading its optical density every hour. The minimal medium of Shepherdet al. [12], with glucose (15 g/L) and biotin was modified: this vitamin was eliminated and the concentration of glucose was gradually lowered to 0.5 g/L. At 5 g/L of glucose and without biotin very good growth was obtained. Based on our results during the first 30 hours of growth, biotin has no influence on the yeast's growth. This medium would be useful for the study of the physiology ofC. albicans during the first period of its development.     

A combined atomic force microscopy imaging and docking study to investigate the complex between p53 DNA binding domain and Azurin

The tumor suppressor p53 interacts with the redox copper protein Azurin (AZ) forming a complex which is of some relevance in biomedicine and cancer therapy. To obtain information on the spatial organization of this complex when it is immobilized on a substrate, we have used tapping mode‐atomic force microscopy (TM‐AFM) imaging combined with computational docking. The vertical dimension and the bearing volume of the DNA binding domain (DBD) of p53, anchored to functionalized gold substrate through exposed lysine residues, alone and after deposing AZ, have been measured by TM‐AFM. By a computational docking approach, a three‐dimensional model for the DBD of p53, before and after addition of AZ, have been predicted. Then we have calculated the possible arrangements of these biomolecular systems on gold substrate by finding a good agreement with the related experimental distribution of the height. The potentiality of the approach combining TM‐AFM imaging and computational docking for the study of biomolecular complexes immobilized on substrates is briefly discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Quantifying the effect of brush layering on slope stability

Soil bioengineering techniques that use vegetation as a structural element gained popularity in the field of natural and man-made slope stabilisation due to their ability to combine safety and environmental conservation elements. In spite of such popularity, little research has been done to quantify their effect on slope stability. This work presents a simple scheme for the evaluation of the Factor of Safety for slopes reinforced by brush layering, which is one of the most common techniques adopted in slope stabilisation works. The proposed model is based on the limit equilibrium principle and accounts for geotechnical soil properties (cohesion, friction angle, unit weight of soil), soil saturation, slope steepness, and brush layer design parameters (number of stems per meter, length and diameter of stems, distance between brush layers). The model provides the value of the Factor of Safety for a given slope and soil depth. Laboratory pullout tests were carried out in order to estimate relevant parameters of cuttings of purple willow (Salix purpurea L.) and to perform a slope stability analysis via the model.     

Characterization of Secondary Metabolites,Biological Activity and Glandular Trichomes of Stachys tymphaea Hausskn. from the Monti Sibillini National Park (Central Apennines,Italy)

Stachys tymphaea (Lamiaceae) is a perennial herb growing in forest openings and dry meadows of central and southern Italy. It was investigated for the first time here, determining the content of secondary metabolites, the micromorphology of glandular trichomes, the histochemical localization of secretion, and the biological activity of the volatile oil, namely, the cytotoxic, antioxidant, and antimicrobial properties. The plant showed a peculiar molecular pattern, being rich of biophenolic compounds as flavonoids, phenylethanoid glycosides, and caffeoylquinic acid derivatives, but poor of iridoids, which are known as marker compounds of the genus Stachys. The essential oil was characterized by GC‐FID and GC/MS analyses, revealing a high percentage of sesquiterpene hydrocarbons (54.6%), with germacrene D (30.0%) and (E)‐β‐farnesene (12.4%) as the most abundant compounds, while other main components were representatives of the diterpenes (19.2%), represented mainly by (E)‐phytol (11.9%). This composition supported the taxonomic relationships in the genus Stachys, which comprises oil‐poor species producing essential oils rich in hydrocarbons, with germacrene D as one of the predominant components. The micromorphological study revealed three types of glandular hairs, i.e., Type A peltate trichomes, being the primary sites of essential oil biosynthesis, Type B short‐stalked trichomes, typical mucopolysaccharide producers, and Type C long capitate trichomes, secreting a complex mixture of both lipophilic and hydrophilic substances, with a major phenolic fraction. Moreover, the MTT assay revealed the potential of the volatile oil to inhibit A375, HCT116, and MDA‐MB 231 tumor cells lines (IC₅₀ values of 23.9–34.4 μg/ml).