13,639 research outputs found
Electrophoretic Demonstration of the Hybrid Origin of the Gynogenetic Teleost \u3cem\u3ePoecilia formosa\u3c/em\u3e
Human serum albumin crystals and method of preparation
Human serum albumin (HSA) crystals are provided in the form of tetragonal plates having the space groups P42(sub 1)2, the crystals being grown to sizes in excess of 0.5 mm in two dimensions and a thickness of 0.1 mm. Growth of the crystals is carried out by a hanging drop method wherein a precipitant solution containing polyethylene glycol (PEG) and a phosphate buffer is mixed with an HSA solution, and a droplet of mixed solution is suspended over a well of precipitant solution. Crystals grow to the desired size in 3 to 7 days. Concentration of reagents, pH and other parameters are controlled within prescribed limits. The resulting crystals exhibit a size and quality such as to allow performance of x ray diffraction studies and enable the conduct of drug binding studies as well as genetic engineering studies
A Component Methodology to Assess The Impact of Protein Imports on the U.S. Dairy Industry
This paper provides an assessment of the protein content of U.S. trade in dairy products and their potential impact on U.S. milk prices. The protein in imports of MPC, Casein & Albumins accounted for 5-6 percent of protein in total U.S. consumption during the period 1997-2002.Livestock Production/Industries,
The influence of long-term inputs of catch crops and cereal straw on yield, protein composition and technological quality of a spring and a winter wheat
Under conditions of restricted nitrogen (N) input such as in organic farming systems, crop N uptake must rely on N mineralised from applied animal manure, crop residues and native soil organic matter. Scarcity of N may impede the production of quality grain for bread production, and input and retention of N in soil are therefore important parameters for soil fertility. Toretain N in the crop-soilsystem, catch crops may be grown in breaks between main crops where they provide a significant sink for N mineralised in late summer and autumn (Thomsen, 2005). In corporation of straw may likewise retain mineralised N by microbial immobilisation (Christensen, 1986) and will also directly add to the N mineralisation potential when the N supplied in the straw accumulates (Thomsen & Christensen, 2004). Under northern European conditions, winter wheat may generally be of lower quality than spring wheat, but winter wheat has a higher yield potential. When the N uptake is mainly based on N mineralised from either applied or indigenous soil organic matter, however, this may even out the quality difference between winter and spring wheat as the longer growing season of winter wheat may boost its N utilisation. Growing conditions are highly important for protein quantity whereas main lygenetic factors influence protein composition (Amesetal., 1999; Luoetal., 2000). Wheat grain proteins have been classified as albumins, globulins, gliadins and glutenins on the basis of their solubility (Osborne, 1907). Reverse-phase (RP) high performance liquid chromatography (HPLC) allows the quantitative determination of these different flour protein groups together with single proteins (α5-, α1,2-, α-, γc-type gliadins, x- and γ-type high (HMW) and low (LMW) molecular weights subunits of glutenin) (Wieser & Seilmeier, 1998). The proteins can also be divided into polymers (glutenins) or monomers (gliadins, albumins, globulins) based on their aggregating properties. The polymeric proteins are critical for governing wheat flour processing properties, and their quantity and size distribution reliably measured by size-exclusion (SE) HPLC techniques have been shown to be important indicators of baking quality (Dachkevitch & Autran, 1989; Bateyetal., 1991). The aim of this study was to examine whether wheat yield and baking quality determined by chromatographic techniques together with rheological and chemical quality measurements could be improved by combining agronomic strategies consisting of wheat cultivars and long-term organic matter inputs. The variables tested were (A) a winter wheat and a spring wheat cultivar, (B) three catch crop strategies and (C) four straw incorporation rates
Chromosomal control of wheat endosperm proteins. A critical review.
Progress made in the chromosomal location of structural genes for wheat endosperm proteins, and in the study of the regulation and quantitative expression of these genes, by using aneuploids and by related techniques, is critically evaluated. Recommendations for future work are proposed
Binding of Oxovanadium(IV) Complexes to Blood Serum Albumins
In this work the binding of VIVO2+ and VIVO-complexes to
serum albumins {human serum albumin (HSA), bovine serum albumin
(BSA) and porcine serum albumin (PSA)} are studied using circular
dichroism (CD), electron paramagnetic resonance (EPR) and visible
absorption spectroscopy. The results confirm previous findings that
VIVO2+ occupies at least two types of binding sites on albumin: ‘the
strong vanadium binding site’ (designated by VBS1) and ‘the weak
vanadium binding sites’ (designated by VBS2). VBS1 binds 1 mol
equivalent of VIVO2+. On the other hand VBS2 correspond to binding
of several mol equivalents of VIVO, and studies done with PSA in the
presence of excess ZnII ions indicate that VSB2 corresponds to two
distinct types of sites. The hyperfine coupling constant Az for VIVO2+
binding at VBS2 on HSA and BSA are all very similar (~168 × 10-4
cm-1) but differ slightly on PSA (~166 × 10-4 cm-1) due to differences
in the binding sets. When (VIVO)-HSA systems are titrated with maltol
ternary species of (maltol)m(VIVO)mHSA and (maltol)2m(VIVO)mHSA
stoichiometry form which are clearly distinguishable from the binary
(VIVO)-HSA system by the type and intensity of the CD spectra
recorded. Changes are also observable in the intensity of the X-band
EPR spectra, but not much in the hyperfine coupling constants Az,
which are all in the range 166-167 × 10-4 cm-1. The results further
demonstrate that the presence of maltol may enhance the binding of
VIVO to albumin
Translational and rotational motions of albumin sensed by a non-covalent associated porphyrin under physiological and acidic conditions: a fluorescence correlation spectroscopy and time resolved anisotropy study.
The interaction between a free-base, anionic water-soluble porphyrin, TSPP, and the drug carrier protein, bovine serum albumin (BSA) has been studied by time-resolved fluorescence anisotropy (TRFA) and fluorescence correlation spectroscopy (FCS) at two different pH-values. Both rotational correlation times and translational diffusion times of the fluorescent species indicate that TSPP binding to albumin induces very little conformational changes in the protein under physiological conditions. By contrast, at low pH, a bi-exponential decay is obtained where a short rotational correlation time (¿ int¿=¿1.2 ns) is obtained, which is likely associated to wobbling movement of the porphyrin in the protein binding site. These physical changes are corroborated by circular dichroism (CD) data which show a 37% loss in the protein helicity upon acidification of the medium. In the presence of excess porphyrin formation of porphyrin J-aggregates is induced, which can be detected by time-resolved fluorescence with short characteristic times. This is also reflected in FCS data by an increase in molecular brightness together with a decrease in the number of fluorescent molecules passing through the detection volume of the sampl
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Anolis oculatus
Number of Pages: 4Integrative BiologyGeological Science
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