Direct Method for Continuous Determination of Iron Oxidation by Autotrophic Bacteria

A method for direct, continuous determination of ferric ions produced in autotrophic iron oxidation, which depends upon the measurement of ferric ion absorbance at 304 nm, is described. The use of initial rates is shown to compensate for such changes in extinction during oxidation, which are due to dependence of the extinction coefficient on the ratio of complexing anions to ferric ions. A graphical method and a computer method are given for determination of absolute ferric ion concentration, at any time interval, in reaction mixtures containing Thiobacillus ferrooxidans and ferrous ions at known levels of SO(4) (2+) and hydrogen ion concentrations. Some examples are discussed of the applicability of these methods to study of the rates of ferrous ion oxidation related to sulfate concentration.     

Secondary ion mass spectrometry for sulfoglycolipids: application of negative ion detection

A series of underivatized sulfoglycolipids (SM4g, lyso-SM4g, SM4s, SM3, SM2, SB2, and SB1a) from various tissues were analyzed by both positive (POS-SI-MS) and negative (NEG-SI-MS) secondary ion mass spectrometry. By POS-SI-MS were detected the molecular ions of sulfoglycolipids in the form with sodium or potassium together with some fragment ions useful for the carbohydrate sequence determination. The analysis of monosulfogangliotriaosyl- or monosulfogangliotetraosylceramide and bis-sulfoglycolipid was difficult due to noise in the high mass region. On the other hand, NEG-SI-MS of sulfoglycolipids gave more intense signals from molecular ion of (M-H)- for monosulfoglycolipids and [M-H+Na)-H)- for bis-sulfoglycolipid. Many fragment ions useful for the elucidation of the carbohydrate sequences were also obtained with significant intensities. The fragmentation was assessed to occur at the glycosidic linkages to form ions of the oligosaccharides with or without ceramide. These ions were useful for sugar sequencing and also for distinguishing the differences in the position of the sulfate group. The intensities of saccharide ions without sulfate were lower than those with sulfates. In the case of SB2 and SB1a, containing 2 mol of sulfate ester groups, the molecular ion was detected as [M-H+Na)-H)-. Also, fragment ions with 2 mol of sulfate were detected as the sodium-additive form. It was concluded that NEG-SI-MS is a very useful technique for the structural elucidation of higher sulfoglycolipids.     

Potassium permanganate–glutaraldehyde chemiluminescence system catalyzed by gold nanoprisms toward selective determination of fluoride

Gold and silver nanoparticles (NPs) are shown to exert a positive effect on the chemiluminescence (CL) reaction of permanganate aldehydes. Interestingly, between various shapes examined, Au nanoprisms have the highest beneficial effect. This effect is even more notable in the presence of sodium dodecyl sulfate (SDS) surfactant. UV‐vis spectra and transmission electron microscopy were used to characterize the NP shapes and sizes. Furthermore, it was observed that iron(III) ions can slightly increase CL emission of this system. This intensification is very effective in the presence of fluoride ions (F^–). These observations form the basis of the method for the high sensitive determination of F^– in the 6–1200 nmol L^–1 concentration range, with a detection limit of 2.1 nmol L^–1. The proposed method has good precision and was satisfactorily used in the selective determination of low concentrations of fluoride ion in real samples. Copyright © 2015 John Wiley & Sons, Ltd.     

Quantification of steroid conjugates using fast atom bombardment mass spectrometry

Fast atom bombardment/mass spectrometry or liquid secondary ion mass spectrometry provides the capability for direct analysis of steroid conjugates (sulfates, glucuronides) without prior hydrolysis or derivatization. During the analysis of biologic extracts, limitations on the sensitivity of detection arise from the presence of co-extracted material which may suppress or obscure the analyte signal. A procedure is described for the quantitative determination of dehydroepiandrosterone sulfate in serum which achieved selective isolation of the analyte using immunoadsorption extraction and highly specific detection using tandem mass spectrometry. A stable isotope-labeled analog [( 2H2]dehydroepiandrosterone sulfate) was used as internal standard. Fast atom bombardment of dehydroepiandrosterone sulfate yielded abundant [M-H]- ions that fragmented following collisional activation to give HSO4-; m/z 97. During fast atom bombardment/tandem mass spectrometry of serum extracts, a scan of precursor ions fragmenting to give m/z 97 detected dehydroepiandrosterone sulfate and the [2H2]-labeled analog with a selectivity markedly superior to that observed using conventional mass spectrometry detection. Satisfactory agreement was observed between quantitative data obtained in this way and data obtained by gas chromatography/mass spectrometry of the heptafluorobutyrates of dehydroepiandrosterone sulfate and [2H2]dehydroepiandrosterone sulfate obtained by direct derivatization.     

Indirect photometric ion chromatographic analysis of anions in Haematococcus pluvialis culture media

An indirect photometric ion chromatographic method for the simultaneous determination of chloride, nitrate and sulfate ions was developed and applied to the determination of anions, mainly nitrate, in the alga Haematococcus pluvialis culture media. Using phthalic acid/sodium tetraborate aqueous solution as the mobile phase, anions can be detected indirectly by a UV detector. The calibration curves for these anions gave good linearity from 1 to 1000 g ml^–1.     

Nutritional requirements of Brettanomyces bruxellensis: growth and physiology in batch and chemostat cultures

The nutritional requirements of Brettanomyces bruxellensis have been investigated. Batch culture and chemostat pulse techniques were used to identify growth-limiting nutrients. The study included determination of the essential components of the culture medium and quantification of the effects of the components. Among the components tested, ammonium sulfate and yeast extract had a significant effect on glucose consumption, growth, and ethanol production. However, if the ammonium sulfate concentration is above 2 g/L, an inhibitory effect on B. bruxellensis growth is observed. The yeast extract appears to be the most important and significant component for growth. The maximum amount of synthesized biomass is proportional to the concentration of yeast extract added to the culture broth (in the tested range). Magnesium and phosphate ions are probably not essential for B. bruxellensis. These ions appear to be supplied in sufficient amounts by the yeast extract in the culture medium. Brettanomyces bruxellensis appears to have very low nutritional requirements for growth.     

Gas chromatographic determination of sodium dodecyl sulfate

A gas chromatographic method has been developed for the determination of sodium dodecyl sulfate. The method is sensitive, reasonably accurate, and uninfluenced by the presence of protein. The method depends upon the formation of 1-dodecanol and inorganic sulfate by acidic hydrolysis of sodium dodecyl sulfate (4 n HCl, 2 hr, 100°C). The ether extracted 1-dodecanol is analyzed by standard gas chromatographic techniques.     

Rapid method for determining the stability of streptomycin sulfate powders]

A method applicable for beforehand determination of streptomycin sulfate powder stability by the colour of its solutions is described. It is shown that the results of such a determination satisfactorily coincided with the results of indirect determination of the solution colour after prolonged storage of the powders at room temperature.     

A new method for the determination of N-sulfate in heparin and its analogs.

A new method for the determination of N-sulfate in heparin and its analogs is described. The method is based on the determination of inorganic sulfate liberated by deamination with nitrous acid. The accuracy, simplicity, and validity of this method are evaluated by comparing it with previous methods.     

Automated determination of organic sulfur compounds. I. Spectrophotometric measurement of inorganic sulfate by low-pressure exchange chromatography

A method for determination of inorganic sulfate is described which represents the terminal step of an automated assay of organic sulfur compounds in biological fluids. Nanomole quantities of inorganic sulfate were applied to a barium chloranilate column. Corresponding amounts of chloranilate ion, released as a result of an exchange reaction, were then measured by uv absorption at 313 nm. The reproducibility and sensitivity of the method and a calibration curve are reported.     

Changes in plasma levels of estrone sulfate and estrone in the pregnant ewe around parturition

A method for the extraction, separation and measurement of estrone sulfate and estrone in a single plasma sample is described. The method has been applied to the determination of plasma levels of estrone sulfate and estrone in pregnant ewes over the period 60 hr before to 20 hr after parturition. The study revealed that the plasma levels of estrone sulfate and estrone began to increase about 40 hr before parturition, reached a peak at parturition and then declined rapidly to levels below the sensitivity of the method by 15 hr postpartum. The peak level of estrone sulfate recorded at parturition was 103 pmol (38 ng) per ml of plasma which was approximately 30 times greater than the corresponding peak level of estrone.     

Crystallization and a preliminary X-ray crystallographic study of alpha-amylase from Bacillus licheniformis

alpha-Amylase from Bacillus licheniformis has been crystallized by the hanging-drop vapor diffusion method in the presence of calcium ions using ammonium sulfate as precipitant. The crystals are tetragonal, belonging to the space group P4(1)2(1)2 (or P4(3)2(1)2), with unit cell dimensions of a = 119.9 and c = 85.4 A. The asymmetric unit contains one molecule of alpha-amylase, with a crystal volume per protein mass (VM) of 2.78 A3/Da. The crystals diffract to better than 2.0 A Bragg spacing when exposed to synchrotron X-rays and they are reasonably stable in the X-ray beam. Thus the crystals are suitable for structure determination at high resolution by X-ray methods.     

不同硫取代度昆布多糖硫酸酯的合成及理化性质初步研究

目的:对昆布多糖进行不同硫取代度的硫酸酯化修饰,并对其产物的硫酸基含量、糖含量与分子量进行检测,为研究不同硫取代度昆布多糖硫酸酯的生物活性奠定物质基础。方法:采用氯磺酸-吡啶法对昆布多糖进行硫酸化修饰,通过改变硫酸化修饰条件,来制取不同硫酸基取代度的昆布多糖硫酸酯;利用盐酸水解-硫酸钡比浊法测定昆布多糖硫酸酯的硫酸基含量,并通过公式求得其硫取代度;用苯酚-硫酸法测定昆布多糖硫酸酯的多糖含量,并使用HPGPC法测定其分子量。结果:两种不同硫取代度昆布多糖硫酸酯的硫酸基含量分别为37.8%、45.92%,取代度分别为1.07、1.51,糖含量分别为44.52%、37.19%,分子量分别为13000、16000。结论:利用氯磺酸-吡啶法对昆布多糖进行硫酸酯化修饰,该方法可以获取不同取代度产物,酯化率高。     

Identification and biochemical analysis of a homolog of a sulfate transporter from a vanadium-rich ascidian Ascidia sydneiensis samea

Background

Several species of ascidians accumulate extremely high levels of vanadium ions in the vacuoles of their blood cells (vanadocytes). The vacuoles of vanadocytes also contain many protons and sulfate ions. To maintain the concentration of sulfate ions, an active transporter must exist in the blood cells, but no such transporter has been reported in vanadium-accumulating ascidians.

Methods

We determined the concentration of vanadium and sulfate ions in the blood cells (except for the giant cells) of Ascidia sydneiensis samea. We cloned cDNA for an Slc13-type sulfate transporter, AsSUL1, expressed in the vanadocytes of A. sydneiensis samea. The synthetic mRNA of AsSUL1 was introduced into Xenopus oocytes, and its ability to transport sulfate ions was analyzed.

Results

The concentrations of vanadium and sulfate ions in the blood cells (except for the giant cells) were 38 mM and 86 mM, respectively. The concentration of sulfate ions in the blood plasma was 25 mM. The transport activity of AsSUL1 was dependent on sodium ions, and its maximum velocity and apparent affinity were 2500 pmol/oocyte/h and 1.75 mM, respectively.

General significance

This could account for active uptake of sulfate ions from blood plasma where sulfate concentration is 25 mM, as determined in this study.     

Determination of polyanionic macromolecules by size-exclusion chromatography

This report presents an extension of a method developed for determination of dextran sulfate in rat serum. The drug is a negatively charged polysaccharide with a molecular mass of 8000. It is fractionated by molecular size and separated from serum components by high-performance size-exclusion chromatography. Sensitive detection is achieved by the post-column complexation of the analyte with 1,9-dimethylmethylene blue (DMMB). A metachromatic complex is formed; the absorbance maximum of the complex is shifted from that of the free dye. Various glycosaminoglycans and other macromolecular polyanions interact with DMMB. Several can be determined using the chromatographic conditions developed for dextran sulfate. The method provides a simple procedure for quantitation of these compounds. Compared to spectrophotometric assays, less sample preparation is required, selectivity is enhanced, and molecular mass information is provided. With modification of eluent composition, dye concentration, and detection wavelength, the method can be validated for determination of additional compounds.     

Application of isotope dilution analysis to the determination of sulfate in glycoproteins and oligosaccharides

Isotope dilution analysis, using a probe of ³⁵S-labeled BaSO₄, is proposed for the determination of sulfate in hydrolysates of glycoproteins and other glycoconjugates. A scaled-down version of the method of Klockow is presented. A modified radioassay in strongly acidic conditions, effective in the range of 0.5 to 10 nmol sulfate per sample, has been developed.     

Optimized extraction of glycosaminoglycans from normal and osteoarthritic cartilage for glycomics profiling

Articular cartilage is a highly specialized smooth connective tissue whose proper functioning depends on the maintenance of an extracellular matrix consisting of an integrated assembly of collagens, glycoproteins, proteoglycans (PG), and glycosaminoglycans. Isomeric chondroitin sulfate glycoforms differing in position and degree of sulfation and uronic acid epimerization play specific and distinct functional roles during development and disease onset. This work introduces a novel glycosaminoglycan extraction method for the quantification of mixtures of chondroitin sulfate oligosaccharides from intact cartilage tissue for mass spectral analysis. Glycosaminoglycans were extracted from intact cartilage samples using a combination of ethanol precipitation and enzymatic release followed by reversed-phase and strong anion exchange solid-phase extraction steps. Extracted chondroitin sulfate glycosaminoglycans were partially depolymerized using chondroitinases, labeled with 2-anthranilic acid-d(4) (2-AA) and subjected to size exclusion chromatography with online electrospray ionization mass spectrometric detection in the negative ion mode. The method presented herein enabled simultaneous determination of sulfate position and uronic acid epimerization in juvenile bovine and adult human cartilage samples. The method was applied to a series of 13 adult human cartilage explants. Standard deviation of the mean for the measurements was 1.6 on average. Coefficients of variation were approximately 4% for all compositions of 40% or greater. These results show that the new method has sufficient accuracy to allow determination of topographical distribution of glycoforms in connective tissue.     

A fast and simple turbidimetric method for the determination of sulfate in sulfate-reducing bacterial cultures

A standard turbidimetric assay for the determination of sulfate in water was modified with the objective of achieving a quick and simple method for monitoring the decrease of sulfate in cultures of sulfate-reducing bacteria. The effects of sulfate concentration, mixing time and the ratio of sample to conditioning reagent were optimized using a central composite face-centered response surface model design. The results suggested that a mixing time of 30 s resulted in smaller absorbance variance, the variance in absorbance measurements tended to increase with concentration of sulfate and that the ratio between the amount of conditioning reagent and sample had no significant influence on the absorbance variance. The modified assay thus developed is simple and quick, and covers a comparatively large sulfate concentration range (0-5 mM) compared to the standard turbidimetric assay.     

A radioimmune study of the effect of bromodeoxyuridine on the synthesis of proteoglycan by differentiating limb bud cultures.

A radioimmune assay has been developed for the quantitative determination and the qualitative identification of core protein of cartilage chondroitin sulfate proteoglycan. Utilizing this method it has been shown that during differentiation of chick limb bud mesenchyme to cartilage, there is a marked augmentation of synthesis of core protein. Treatment with 5-bromo-2′-deoxyuridine results in an irreversible inhibition of synthesis of cartilage-specific chondroitin sulfate proteoglycan.     

Determination of protein-bound dodecyl sulfate by gas chromatography.

Sodium dodecyl sulfate has been determined by a gas chromatographic method. The sulfate group is hydrolyzed, and the liberated dodecanol is determined by gas chromatography using an SE-30 column. Dodecanol is clearly resolved from the common fatty acid methyl esters. The presence of proteins or phospholipids in the sample seems to have no effect on the determination. Using a conventional gas chromatograph, 0.5 to 1.0 μg of dodecyl sulfate in the sample can be detected.