A study of the water-soluble proteins of the seeds of the cotton plants Gossypium hirsutum and G. barbadense

It has been shown by electrophoresis in polyacrylamide gel that different enzymes with similar electrophoretic mobilities may be localized in one and the same zone of water-soluble cottonseed proteins. Some zones not stained by the usual protein dyes also possess enzymatic activity. It has been established that the majority of the electrophoretic fractions consist of a series of polypeptides with different molecular weights, mainly of low-molecular-weight nature. The results are given of an investigation of the peroxidase, -amylase, lipase, NADH-DCPIP oxidoreductase, and NADPH-DCPIP oxidoreductase activities of the water soluble fraction of the proteins of the seeds of the species mentioned.Institute of Experimental Plant Biology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 488–491, July–August, 1986.     

Histones of the cotton plant. Molecular characteristics of histone H1

A characterization of the histones of two varieties of the cotton plant,Gossypium hirsutum andG. barbadense, has been given with the aid of various electrophoretic systems. Their molecular weights have been determined. An analysis has been made of the cleavage of histone H1 at tyrosine residues. The positive charge and the molecular length of histone H1 have been determined by the method of incomplete succinylation.     

Analysis of citrate-capped gold and silver nanoparticles by thiol ligand exchange capillary electrophoresis

We report on the capillary electrophoretic behavior of citrate-capped gold and silver nanoparticles in aqueous medium when applying a ligand-exchange surface reaction with thiols. Gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) of similar size (39?±?6 and 41?±?7 nm, respectively) and shape were synthesized, covered with a citrate shell, and characterized by microscopic and spectroscopic techniques. The analysis of these NPs by CE was accomplished by using a buffer solution (pH 9.7; 40 mM SDS, 10 mM CAPS; 0.1 % methanol) containing the anions of thioctic acid or thiomalic acid. These are capable of differently interacting with the surface of the AuNPs and AgNPs and thus introducing additional negative charges. This results in different migration times due to the formation of differently charged nanoparticles. Figure

Capillary electrophoretic behavior of citrate-capped gold and silver nanoparticles (NPs) in aqueous medium when applying a ligand-exchange surface reaction with thiols (thioctic and thiomalic acids), which introduces additional negative charges, has been studied     

A study of the hydration of ribonuclease A using isothermal calorimetry

This work is part of a systematic study undertaken to find the excess thermodynamic functions of binary protein–water systems. Isothermal calorimetry and water sorption measurements were applied to characterize the hydration dependencies of the excess thermodynamic functions. The advantages of our methodology are (i) we are able to simultaneously determine the excess partial quantities of water and proteins; (ii) these thermodynamic quantities can be determined in the entire range of water content. Here, in particular, the excess partial enthalpies of water and bovine pancreatic ribonuclease A (RNase A) have been determined. The excess partial enthalpies for RNase A are compared with the published data for several unrelated globular proteins (lysozyme, chymotrypsinogen A, serum albumin, lactoglobulin). These biomacromolecules represent a series of proteins in which the hydrophobicity of proteins is gradually changed in a wide range. It was found that the excess partial quantities for the studied proteins are determined by the hydration of the hydrophilic and hydrophobic protein groups. The more hydrophilic a protein, the more significant a hydrophilic hydration contribution is and vice versa. RNase A is the most hydrophilic protein under the study. This protein has the most significant hydrophilic hydration contribution. Lactoglobulin is the most hydrophobic protein under the study. This protein has the most significant hydrophobic hydration contribution.     

Isolation and properties of transferrin messenger RNA from rat liver

Highly purified transferrin mRNA characterized by electrophoretic and sedimentational homogeneity has been obtained from rat liver, with a sedimentation coefficient of 20S and a molecular weight of 0.86 MD. In a system consisting of a lysate of rabbit reticulocytes the Tf-mRNA programs the synthesis of an immunoreactive precursor of transferrin with a molecular weight of 82 kD. More than 50% of the nucleotide sequence of Tf-mRNA is present in the paired state.     

Relaxation properties and structures of polymer nanocomposites based on modified organoclays

Nanocomposite materials composed of HDPE and new guanidine-containing organoclays have been investigated. The basic changes in the relaxation properties of HDPE after the addition of guanidine-containing organoclays that vary in composition and content have been found. It has been shown that, depending on their structures and affinities for the polymer, guanidine-containing modifiers of montmorillonite have different effects on the structure and relaxation properties of the polymer.     

The Effect of Arg on the Structure Perturbation and Chaperone Activity of α-Crystallin in the Presence of the Crowding Agent,Dextran

α-Crystallin is a protein that is expressed at high levels in all vertebrate eye lenses. It has a molecular weight of 20 kDa and is composed of two subunits: αA and αB. α-Crystallin is a member of the small heat shock protein (sHsps) family that has been shown to prevent protein aggregation. Small molecules are organic compounds that have low molecular weight (<800 Da). Arginin (Arg) is a small molecule and has been shown to prevent protein aggregation through interaction with partially folded intermediates. In this study, the effect of Arg on the chaperone activity of α-crystallin in the presence of dextran, as a crowding agent, against ordered and disordered aggregation of different target proteins (α-lactalbumin, ovotransferrin, and catalase) has been investigated. The experiments were done using visible absorption spectroscopy, ThT-binding assay, fluorescence spectroscopy, and CD spectroscopy. The results showed that in amorphous aggregation and amyloid fibril formation, both in the presence and absence of dextran, Arg had a positive effect on the chaperone action of α-crystallin. However, in the presence of dextran, the effect of Arg on the chaperone ability of α-crystallin was less than in its absence. Thus, our result suggests that crowding interior media decreases the positive effect of Arg on the chaperone ability of α-crystallin. This is a very important issue, since we are trying to find a mechanism to protect living cells against the toxic effect of protein aggregation.     

TG-FTIR kinetic study of the thermal cleaning of wood laminated flooring waste

The enhancement of wood waste is a promising solution for the production of energy from renewable resources. Nevertheless, wood waste often needs a preliminary treatment step to remove pollutants present in the material. The thermal cleaning of wood laminated flooring (WLF) waste is studied through thermogravimetric and FTIR analyses. As a first step, it has been shown, through non iso-thermal tests, that degradation temperature ranges for wood and additives (aminoplast resins) are different, making it possible to proceed to a thermal cleaning through a low temperature pyrolysis. It has also been highlighted that chemical linkages between the different components of WLF waste influence their own thermal behaviour making it difficult to predict the thermal behaviour of the whole material. Fourier transform infra-red spectrometry analyses reveal that NH₃ and HNCO are the main nitrogen-containing gases produced during pyrolysis, which highlights the pyrolysis efficiency in terms of nitrogen (i.e., resin) removing. Lastly, thermal degradation of wood and WLF has been modelled to provide information for reactor designing.     

Top-Down and Bottom-Up Identification of Proteins by Liquid Extraction Surface Analysis Mass Spectrometry of Healthy and Diseased Human Liver Tissue

Liquid extraction surface analysis mass spectrometry (LESA MS) has the potential to become a useful tool in the spatially-resolved profiling of proteins in substrates. Here, the approach has been applied to the analysis of thin tissue sections from human liver. The aim was to determine whether LESA MS was a suitable approach for the detection of protein biomarkers of nonalcoholic liver disease (nonalcoholic steatohepatitis, NASH), with a view to the eventual development of LESA MS for imaging NASH pathology. Two approaches were considered. In the first, endogenous proteins were extracted from liver tissue sections by LESA, subjected to automated trypsin digestion, and the resulting peptide mixture was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) (bottom-up approach). In the second (top-down approach), endogenous proteins were extracted by LESA, and analyzed intact. Selected protein ions were subjected to collision-induced dissociation (CID) and/or electron transfer dissociation (ETD) mass spectrometry. The bottom-up approach resulted in the identification of over 500 proteins; however identification of key protein biomarkers, liver fatty acid binding protein (FABP1), and its variant (Thr→Ala, position 94), was unreliable and irreproducible. Top-down LESA MS analysis of healthy and diseased liver tissue revealed peaks corresponding to multiple (~15–25) proteins. MS/MS of four of these proteins identified them as FABP1, its variant, α-hemoglobin, and 10 kDa heat shock protein. The reliable identification of FABP1 and its variant by top-down LESA MS suggests that the approach may be suitable for imaging NASH pathology in sections from liver biopsies. Graphical Abstract

?     

Purification of nerve growth factor from the venom of the Central Asian cobraNaja oxiana

A highly purified electrophoreticaly homogeneous protein with a NGF activity of 10·10⁵ BU/mg of protein have been isolated from the venom of the Central Asian cobra by gel-filtration and ion-exchange chromatography followed by preparative isolectric focusing in a thin layer of Sephadex. It has been shown that the NGF isolated is characterized by a molecular weight in the range of 20–30 kD and a pI value of about 7.0.     

Rapid purification of pig heart fumarase by general ligand chromatography

A rapid method for the purification of fumarase from pig heart muscle has been developed using general ligand chromatography with adenosine triphosphate as ligand. Fumarase exhibited distinctive elution patterns from several types of nucleotide-agarose matrices, which may prove of value in distinguishing putative isozymic forms. Fumarase purified from both soluble and particulate fractions of cardiac tissue appeared to be identical in terms of subunit molecular weight, electrophoretic mobility on cellulose acetate, substrate kinetics, and inactivation by several inhibitors. When fresh cardiac tissue was suspended in sucrose medium, both fumarase and citrate synthase were released from the mitochondria to about the same extent (10%). However, fumarase release was increased approximately three-fold, while the release of titrate synthase increased only slightly, when tissue which had been frozen and thawed was suspended in sucrose medium.     

Immobilization of fumarase and malate dehydrogenase on agarose efficiency of activity as a function of the enzyme ratio

Two enzymes, L-malate dehydrogenase, L-malate: NAD⁺ oxidoreductase (EC 1.1.1.37) and fumarase, L-malate hydrolyase (EC 4.2.1.2) were immobilized on a (Sepharose 4B) resin by the cyanogen bromide method. Studies showed that the matrix-immobilized fumarase retains the same characteristics as the free enzyme, while the matrix-immobilized malate dehydrogenase has reduced activity. The activity of the coupled enzymes is more enzymeconcentration dependent than the free enzymes, and at a ratio of 0.3 (fumarase: malate dehydrogenase) the simultaneously coupled immobilized enzymes become a better catalytic system. Individually immobilized enzymes, mixed to form a coupled system, yielded the poorest catalytic action.     

Some improvements in the estimation of137Cs in urine by the AMP-chlorostannate method

An accurate and reliable method has been developed for the estimation of radiocesium in urine. Initially cesium is adsorbed on ammonium phosphomolybdaste (AMP) precipitate and separated by ion exchange from other contaminants. Cesium thus separated is estimated as cesium chlorostannate, Cs₂SnCl₆, from a 50 (v/v)% solution of concentrated HCl in ethyl alcohol. While the results are in good agreement with the values obtained by γ-spectrometry using a Marinelli beaker in its range of applicability, the present method has a much lower detection limit. It is observed that the method has significant advantages over the methods available with respect to analysis time, accuracy and detection limits.     

A Mathematical Analysis of the Selective Enrichment of NECEEM-Based Non-SELEX

Non-Systematic Evolution of Ligands by EXponential enrichment (SELEX)selection of aptamers, a novel technology for aptamer selection from libraries of random DNA (or RNA) sequences, involves repetitive steps of partitioning without polymerase chain reaction (PCR) amplification between them. This selection is based on non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) and has exceptionally high efficiency. In this paper, a mathematical analysis was carried out to predict the levels of enrichment of non-SELEX selection under different conditions such as different protein concentrations and different efficiencies of partitioning. Investigated results suggest that the magnitude of the bulk affinity (k _d) being 10⁴ or 10⁵ μM for the initial pool has no obvious effect on selective enrichment and that the first, second, and third rounds of non-SELEX selection have different optimum protein concentration values [T _f] that give maximum enrichment levels when [T _f] ranges from 0.0005 to 0.5 μM. The significance of analyzing selective enrichment of NECEEM-based non-SELEX with the efficiency of partitioning target-bound ligands from free ligands has been demonstrated.     

Characteristics of the molecular-mass parameters and viscosities of solutions of the lipopolysaccharide-protein complex fromYersinia pseudotuberculosis

The lipopolysaccharide-protein complex (LPPC) fromY. pseudotuberculosis isolated by extraction with trichloroacetic acid has been investigated by the methods of gel permeation chromatography, light scattering, and viscometry. The molecular-mass distributions of aggregates of the LPPC in water, 0.03 M Tris-HCl buffer (pH 8) and 0.1 M sodium chloride have been determined. A dependence of the polydispersity and dimensions of the aggregates on the concentration of the polymer and on the ionic strength of the solvent has been shown. It has been established that in water the LPPC has a high characteristic viscosity which falls with an increase in the ionic strength of the solution.     

Isolation of nonprotamine proteins from the nuclei of the gonad cells of the Russian sturgeonAcipenser güldenstadti

Eight nonprotamine proteins have extracted from the nuclei of the cells of the gonads of the Russian sturgeon with 0.35 M sodium chloride solution followed by fractionation of carboxymethyl-Sephadex G-25 and desalting on Bio-Gel P-2, and their amino acid compositions have been determined.     

Development of a PIXE method at high energy with the ARRONAX cyclotron

The high energy PIXE (HEPIXE) method is a multi-elemental non-destructive ion beam analysis technique. It is based on the detection of the X-ray emitted due to the interaction of high energy particle beam with a sample. This technique is fast and allows the analysis of heavy and medium elements in thin (μm), thick (mm) and multilayer samples. At the ARRONAX facility (Nantes, France), the HEPIXE method has been used to determine the composition of natural and synthetic sodalites. Photochromic properties of these samples are supposed to come from the trace elements (concentration in the ppm range) present in the samples. Taking advantage of the 70 MeV proton beam available at our facility, the HEPIXE method has been also used to study multilayer samples. It has been shown that it is possible to determine the composition of each layer, their thicknesses and their depth position by analyzing the recorded X-ray spectra.     

Influence of chemical nature of aerosilogel surface on proton conductivity of the Nafion-containing composites

Aerosilogel modified with hydroxylaluminum (=Al-OH) groups has been synthesized via the molecular layering procedure, and aerosilogel modified with aminopropylsilyl groups [≡Si(CH₂)₃NH₂] has been prepared via chemisorption of (3-aminopropyl)triethoxysilane. The modified aerosilogel have been further used to prepare composite Nafion-containing electrolytes Nafion. Electrical conductivity of the produced materials has been studied by impedance spectroscopy. Chemical modification of the gel surface strongly affects proton conductivity of Nafion-containing composites.     

Size and charge characterization of polymeric drug delivery systems by Taylor dispersion analysis and capillary electrophoresis

In this work, Taylor dispersion analysis and capillary electrophoresis were used to characterize the size and charge of polymeric drug delivery nanogels based on polyglutamate chains grafted with hydrophobic groups of vitamin E. The hydrophobic vitamin E groups self-associate in water to form small hydrophobic nanodomains that can incorporate small drugs or therapeutic proteins. Taylor dispersion analysis is well suited to determine the weight average hydrodynamic radius of nanomaterials and to get information on the size polydispersity of polymeric samples. The effective charge was determined either from electrophoretic mobility and hydrodynamic radius using electrophoretic modeling (three different approaches were compared), or by indirect UV detection in capillary electrophoresis. The influence of vitamin E hydrophobicity on the polymer effective charge has been studied. The presence of vitamin E leads to a drastic decrease in polymer effective charge in comparison to non-modified polyglutamate. Finally, the electrophoretic behavior of polyglutamate backbone grafted with hydrophobic vitamin E (pGVE) nanogels according to the ionic strength was investigated using the recently proposed slope plot approach. It was deduced that the pGVE nanogels behave electrophoretically as polyelectrolytes which is in good agreement with the high water content of the nanogels.

Polarography of hexavalent molybdenum in hypophosphorous acid solutions

The polarographic behaviour and determination of Mo(VI) in hypophosphorous acid solutions of concentrations varying from 0.1 to 5.0 mol l^?1 andT=25±0.1 °C have been investigated. It was shown that reduction of MoO ₄ ^2? takes place along a single or two waves depending upon the acid concentration. Microcoulometric experiments have been performed at the limiting region of the different waves obtained at different acid concentrations. A scheme for the mechanism of reduction occuring at theDME has been deduced. A method for analytical determination of Mo(VI) on both the micro- and macro-scales in hypophosphorous acid solutions has been reported. Analysis of a binary mixture Mo(VI)/Cd(II) and a tertiary mixture Mo(VI)/Cd(II)/Zn(II) in mol l^?1 hypophosphorous acid has been investigated.