A comparative NMR and molecular dynamics study of the conformations of bradykinin B1 and B2, B2, and B1-specific receptor antagonists B-9430, B-9436, and B-9858

Extensive proton magnetic resonance experiments were carried out on three bradykinin peptide antagonists B-9430, B-9436, and B-9858 in aqueous solutions as well as in sodium dodecylsulphate micelles (B-9430 and B-9436) and CD₃OH/H₂O (60%/40%) mixtures for B-9858. All three peptides showed no observable secondary structure in aqueous solution. However, in their respective structure-inducing solvents, B-9430 (B₁ and B₂ receptor antagonist) and B-9436 (a B₂ receptor antagonist) exhibit a type II β-turn involving residues 2–5, and B-9430 also exhibits a type II′ β-turn involving residues 6–9 (in sodium dodecylsulfate micellar solutions), whereas B-9858, a B₁-specific receptor antagonist, exhibits only a type II β-turn involving residues 2–5 (in CD₃OH/H₂O solutions). Simulated annealing calculations on B-9858 confirm the experimental conclusions based on the nmr data. In addition, simulated annealing of the (2S, 3aS, 7aS)-octahydroindole-2-carboxylic acid (Oic residue), which is present in two of the three decapeptides studied, show that the one-chair conformation of the six-membered ring predominates, in agreement with the experimental data. The activities of these peptides are compared with their secondary structures and the specific receptor activity appears to depend on the presence of specific amino acid residues, such as N-(2-indanyl)glycine (Nig) and D[α-(2-indanyl)glycine] (D-Igl) as well as on elements of secondary structure. © 1997 John Wiley & Sons, Inc. Biopoly 42: 521–535, 1997     

Exploiting Phosphate-Starved cells of <Emphasis Type="Italic">Scenedesmus</Emphasis> sp. for the Treatment of Raw Sewage

Phosphate depletion is one of the favorable ways to enhance the sewage water treatment with the algae, however, detailed information is essential with respect to internal phosphate concentration and physiology of the algae. The growth rate of the phosphate-starved Scenedesmus cells was reduced drastically after 48 h. Indicating cells entered in the stationary phase of the growth cycle. Fourier Transform Infrared analysis of phosphate-starved Scenedesmus cells showed the reduction in internal phosphate concentration and an increase in carbohydrate/phosphate and carbohydrate/lipid ratio. The phosphate-starved Scenedesmus cells, with an initial cell density of, 1 × 10⁶ cells mL^?1 shows 87% phosphate and 100 % nitrogen removal in 24 h. The normal Scenedesmus cells need approximately 48 h to trim down the nutrients from wastewater up to this extent. Other microalgae, Ankistrodesmus, growth pattern was not affected due to phosphate starvation. The cells of Ankistrodesmus was able to reduce 71% phosphate and 73% nitrogen within 24 h, with an initial cell density of, 1 × 10⁶ cells mL^?1.     

Estimation of Mineral and Trace Element Profile in Bubaline Milk Affected with Subclinical Mastitis

The milk samples from buffaloes of Murrah breed at mid lactation stage, reared at an organised dairy farm, were screened for subclinical mastitis based on bacteriological examination and somatic cell count following International Dairy Federation criteria. Milk samples from subclinical mastitis infected and healthy buffaloes were analysed to evaluate physicochemical alterations in terms of protein, fat, pH, electrical conductivity, chloride, minerals (sodium, potassium and calcium) and trace elements (iron, zinc, copper and selenium). In the present study, protein, fat, zinc, iron, calcium and selenium content was significantly lower (P < 0.001), while pH and electrical conductivity were significantly higher in mastitic milk as compared to normal milk. Concentration of electrolytes mainly sodium and chloride significantly increased with higher somatic cell count in mastitic milk and to maintain osmolality; potassium levels decreased proportionately. Correlation matrix revealed significantly positive interdependences of somatic cell count with pH, electrical conductivity, sodium and chloride. However, protein, fat, calcium and potassium were correlated negatively with elevated somatic cell count in mastitic milk. It is concluded that udder infections resulting in elevated somatic cells may alter the mineral and trace element profile of milk, and magnitude of changes may have diagnostic and prognostic value.     

Net primary production in three bioenergy crop systems following land conversion

Aims Identifying the amount of production and the partitioning to above- and belowground biomass is generally the first step toward selecting bioenergy systems. There are very few existing studies on the dynamics of production following land conversion. The objectives of this study were to (i) determine the differences in aboveground net primary production (ANPP), belowground net primary production (BNPP), shoot-to-root ratio (S:R) and leaf area index in three bioenergy crop systems and (ii) evaluate the production of these three systems in two different land use conversions.Methods This investigation included biometric analysis of NPP on three agricultural sites converted from conservation reserve program (CRP) management to bioenergy crop production (corn, switchgrass and prairie mix) and three sites converted from traditional agriculture production to bioenergy crop production.Important findings The site converted from conventional agriculture produced smaller ANPP in corn (19.03±1.90 standard error [SE] Mg ha^-1 year^-1) than the site converted from CRP to corn (24.54±1.43 SE Mg ha^-1 year^-1). The two land conversions were similar in terms of ANPP for switchgrass (4.88±0.43 SE for CRP and 2.04±0.23 SE Mg ha^-1 year^-1 for agriculture) and ANPP for prairie mix (4.70±0.50 SE for CRP and 3.38±0.33 SE Mg ha^-1 year^-1 for agriculture). The BNPP at the end of the growing season in all the bioenergy crop systems was not significantly different (P = 0.75, N = 8).     

Assessment of Genetic Diversity Among Rice Genotypes with Differential Adaptations to Salinity Using Physio-morphological and Molecular Markers

Breeding for salt tolerance using traditional screening and selection methods have been limited by the complex and polygenic nature of salt tolerance trait. This study was designed to evaluate some of the premium Basmati rice varieties for salt tolerance and to characterize genetic diversity among the rice varieties with different adaptations to saline soils using microsatellite (SSR) and ISSR markers. Plants of nine rice varieties including salt tolerant, salt sensitive and traditional Basmati, were grown in hydroponics using Yoshida solution containing 0 (control, pH 5.0) and 30 mM NaCl (Electrical conductivity 4.8 d/S, pH 5.0) and assessed for salinity tolerance on 1–9 scale as per IRRI standard evaluation system using seedling growth parameters, visual salt injuries and Na-K ratio. Physio-morphological studies showed that traditional Basmati rice varieties (Basmati 370 and HBC19) were more sensitive than the salt sensitive control variety, MI-48. SSR as well as ISSR marker systems generated higher levels of polymorphism and could distinguish between all the 9 rice cultivars. A total of 299 (225 polymorphic) and 437 (430 polymorphic) bands were detected using 28 UBC ISSR primers and 100 welldistributed mapped SSR markers, respectively. ISSR and SSR marker data-sets showed moderate levels of positive correlation (Mantel test, r = 0.43). The ISSR and SSR marker data analyzed using clustering algorithms showed two distinct clusters separating the Basmati (Basmati 370, HBC19 and CSR-30) from other non-aromatic indica (IR36, Pokkali, CSR10 and MI-48) rice varieties indicating greater divergence between Basmati and non-aromatic indica rice genotypes. Marker analysis showed a close relationship among the two traditional (Basmati 370 and HBC19) and cross-bred (CSR30) Basmati rice varieties and greater diversity between the two salt-tolerant genotypes, Pokkali and BR4-10.     

Possible impacts of climate change on hydrologic cycle in Slovakia and results of observations in 1951–2007

The hydrologic cycle in Slovakia is determined mainly by three basic components: precipitation (P), evapotranspiration (E) and runoff (R). The mean annual P total was 747 mm, E sum 476 mm and the mean R was 271 mm in Slovakia in 1951–1980 (E ≈ 0.65P and R ≈ 0.35P). T increase in 1.6°C and annual P decrease in 24 mm (3.1%) were detected in the 1881–2007 period. Regimes of potential and actual evapotranspiration, soil moisture and R have been changed mainly in the southern Slovakia. A physical model for the estimation of the energy balance equation components (total radiation balance and its components, potential and actual evapotranspiration, sensible heat flux) has been developed. Input data are the air temperature and humidity, cloudiness, the number of days with snow cover and precipitation, all measured in the network of 31 meteorological stations in Slovakia since 1951. The 20-year period 1988–2007 was by 0.9°C warmer than the normal period mean. The observed increase is at the upper limit of all climate change scenarios projected for Slovakia in 1991–2001. Annual P totals have not changed significantly, but substantial changes have been found in the P regime. The scenarios show significant changes in the hydrological cycle not only at river basins balance but also in case of soil water balance, mainly in the southern Slovakia.