scholarly journals Changes in intermediate haemoglobins during autoxidation of haemoglobin

1981 ◽  
Vol 195 (2) ◽  
pp. 485-492 ◽  
Author(s):  
A Tomoda ◽  
Y Yoneyama ◽  
A Tsuji
Keyword(s):  
Isoelectric Focusing ◽  
Phosphate Buffer ◽  
Time Course ◽  
Inositol Hexaphosphate ◽  
Reaction Rate Constants ◽  
The Media ◽  
Beta 2 ◽  
Quantitative Changes ◽  
Ph Range ◽  
Experimental Values

The time course of haemoglobin autoxidation was studied under various conditions at 37 degrees C, and the changes in oxyhaemoglobin, intermediate haemoglobins and methaemoglobin during the reaction were analysed by isoelectric focusing on Ampholine/polyacrylamide-gel plates. Under various conditions (10 mM-phosphate buffer, 10 mM-phosphate buffer with 0.1 M-phosphate buffer, 10 mM-phosphate buffer with 0.1 M-NaCl, and 10 mM-phosphate buffer with 0.5 mM-inositol hexaphosphate; pH range 6.6-7.8 each case), the intermediate haemoglobins were found to be present as (alpha 2+ beta 3+)2 and (alpha 3+ beta 2+)2 valency hybrids from their characteristic positions on electrophoresis. Oxyhaemoglobin changed consecutively to (alpha 2+ beta 3+)2 and (alpha 3+ beta 2+)2, which were further oxidized to methaemoglobin, and the amounts of (alpha 3+beta 2+)2 were greater than those of (alpha 2+ beta 3+)2 during the reaction. The modes of the quantitative changes in oxyhaemoglobin, intermediate haemoglobins, and methaemoglobin were very similar in all the media used except for the inositol hexaphosphate addition. In the presence of inositol hexaphosphate, the autoxidation rates were considerably accelerated, and the modes of the changes in the haemoglobin derivatives were also considerably altered; the effects of this organic phosphate were maximal at acidic pH and minimal at alkaline pH. It was concluded that haemoglobin autoxidation proceeds by first-order kinetics through two paths: and (formula: see text). The reaction rate constants (k+1-k+4) best fitting all experimental values obtained by the isoelectric-focusing analysis were evaluated. By using these values, the mechanism of haemoglobin autoxidation is discussed.

scholarly journals Mechanism of methaemoglobin reduction by human erythrocytes

1980 ◽  
Vol 188 (2) ◽  
pp. 535-540 ◽  
Author(s):  
A Tomoda ◽  
M Ida ◽  
A Tsuji ◽  
Y Yoneyama
Keyword(s):  
Methylene Blue ◽  
Isoelectric Focusing ◽  
Rate Constants ◽  
Time Course ◽  
Reaction Rate ◽  
Polyacrylamide Gel ◽  
Human Erythrocytes ◽  
Redox Potentials ◽  
Reaction Rate Constants ◽  
Beta 2

The time course of methaemoglobin reduction in human erythrocytes treated with nitrite was studied at pH 7.4, 37 degrees C, in the presence or absence of Methylene Blue, and the changes in methaemoglobin, intermediate haemoglobins and oxyhaemoglobin during the reaction were analysed by isoelectric-focusing on Ampholine/polyacrylamide-gel plates. In both cases, with or without the dye, the intermediate haemoglobins were found to be present at (alpha 3+beta 2+)2 and (alpha 2+beta 3+)2 valency hybrids from their characteristic position on electrophoresis, but amounts changed consecutively with time. The amount of (alpha 3+beta 2+)2 was always greater than that of the (alpha 2+beta 3+)2 valency hybrid. This result is explained by the differences in redox potentials between alpha- and beta-chains in methaemoglobin tetramer. It was concluded that methaemoglobin was reduced in human erythrocytes through these two different pats: methaemoglobin leads to k+3 (alpha 2+beta 3+)2 leads to k+3 oxyhaemoglobin. The reaction rate constants k'+1 (= k+1+k+3) and k'+2(=k+2+k+4) were estimated from the changes in each component methaemoglobin, intermediate haemoglobins [(alpha 3+beta 2+)2+(alpha 2+beta 3+)2] and oxyhaemoglobin.

scholarly journals Changes in intermediate haemoglobins during methaemoglobin reduction by NADPH-flavin reductase

1979 ◽  
Vol 179 (1) ◽  
pp. 227-231 ◽  
Author(s):  
A Tomoda ◽  
T Yubisui ◽  
A Tsuji ◽  
Y Yoneyama
Keyword(s):  
Isoelectric Focusing ◽  
Rate Constants ◽  
Reaction Rate ◽  
Flavin Reductase ◽  
Inositol Hexaphosphate ◽  
Reaction Rate Constants ◽  
Beta 2

The changes in intermediate haemoglobins produced during methaemoglobin reduction by NADPH-flavin reductase were analysed by an isoelectric-focusing method. The alpha 3+ beta 2+ and alpha 2+ beta 3+ valency hybrids were observed as intermediate haemoglobins and changed consecutively with time during the reaction. On the basis of the analyses, the course of methaemoglobin reduction was found to involve two different pathways: (1) methaemoglobin kappa+1 leads to alpha 3+ beta 2+ kappa+2 leads to oxyhaemoglobin; (2) methaemoglobin kappa+3 leads to alpha 2+ beta 3+ kappa+4 leads to oxyhaemoglobin. The reaction rate constants of each phase (kappa+1–kappa+4) were also estimated. The addition of inositol hexaphosphate to the reaction mixture did not affect the overall reaction. The mechanism of methaemoglobin reduction by NADPH-flavin reductase is discussed on the basis of these results.

HETEROGENEITY OF LONG ACTING THYROID STIMULATING (LATS) – ACTIVITY, THYROGLOBULIN ANTIBODIES AND THYROID MICROSOMAL ANTIBODIES

1973 ◽  
Vol 73 (3) ◽  
pp. 483-488 ◽  
Author(s):  
F. Adlkofer ◽  
H. Schleusener ◽  
L. Uher ◽  
A. Ananos ◽  
C. Brammeier
Keyword(s):  
Isoelectric Focusing ◽  
Graves Disease ◽  
Thyroid Antibodies ◽  
Thyroglobulin Antibodies ◽  
Ph Range ◽  
Long Acting ◽  
Thyroid Microsomal Antibodies

ABSTRACT Crude IgG of sera from 3 patients with Graves' disease, which contained LATS-activity and/or thyroid antibodies, was fractionated by isoelectric focusing in a pH-range between 6.0 to 10.0. LATS-activity was found in IgG-subfractions from pH 7.5 to 9.5, thyroglobulin antibodies and thyroid microsomal antibodies from pH 6.0 to 10.0. It was not possible to separate LATS-activity from the thyroid antibodies by this technique. The results indicate that LATS and the thyroid antibodies are heterogeneous and of polyclonal origin.

Alcohol and the Media: A Review and Critique of the ‘Effects’ Model

1982 ◽  
Vol 3 (2) ◽  
pp. 183-194 ◽  
Author(s):  
Nicholas Dorn ◽  
Nigel South
Keyword(s):  
Point Of View ◽  
Economic Consequences ◽  
Future Research ◽  
General Level ◽  
Alcohol Advertising ◽  
Social Drinking ◽  
The Media ◽  
Quantitative Changes ◽  
And Shifts ◽  
Qualitative Changes

A review of the available empirical material bearing upon the question of alcohol advertising having ‘effects’ on the general level of consumption suggests that this question is insufficiently precise as a basis for research. Studies suggesting some relationship between advertising for particular brands or products and shifts in brand or product use are potentially more interesting, if considered from a point of view that recognises that such shifts may involve shifts in milieux, comparisons, styles and meanings associated with consumption. Future research should be attentive to such qualitative changes in drinking practices attendant upon advertising or preventive campaigns (as well as to quantitative changes). The authors suggest that such quantitative and qualitative changes in drinking practices of individuals and social groups need to be considered within the context of more general, ideological and economic, consequences of alcohol advertising. These consequences-including reinforcement of images about ‘social drinking,’ and shifting of consumers onto more profitable products-consolidate the profitability of the alcohol industry (a consideration more important to the industry than levels of consumption per se). A framework broader than that of ‘effects’ on individuals' levels of consumption is required if health educators are to learn anything from advertising.

scholarly journals Comprehensive analysis of the isozyme composition of laccase derived from Japanese lacquer tree, Toxicodendron vernicifluum

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Mariko Takano ◽  
Masaya Nakamura ◽  
Masanobu Tabata
Keyword(s):  
Isoelectric Focusing ◽  
Laccase Activity ◽  
Maximum Activity ◽  
Acetone Powder ◽  
Blue Color ◽  
Buffer Solution ◽  
Activity Staining ◽  
Water Extracts ◽  
Ph Range ◽  
Toxicodendron Vernicifluum

AbstractWe performed an analysis using isoelectric focusing to comprehensively clarify the isozyme composition of laccase derived from Japanese lacquer tree, Toxicodendron vernicifluum. When water extracts of acetone powder obtained from lacquer were subjected to isoelectric focusing, five bands within pI 7.35–9.30 and nine bands within pI 3.50–5.25 were detected using Coomassie staining. Similarly, laccase activity staining using guaiacol showed five bands within pI 7.35–9.30 and three bands within pI 3.50–4.25. However, laccase activity staining using gallic acid showed remarkable staining within pI 3.50–5.85, whereas staining was very weak within pI 7.35–9.30. When the water extracts of acetone powder were fractionated into the fractions containing bands within pI 7.35–9.30 and pI 3.50–5.85 by SP-Sepharose column chromatography, the former had a blue color and the latter a yellow color. The laccase activity was measured for each of the fractions in buffer solution in the pH range of 2.5–8.0. When syringaldazine, guaiacol, and 2,6-dimethoxyphenol were used as substrates, the yellow fraction showed considerably higher activity than the blue fraction for pH 5.5–7.5. When 3-methylcatechol and 4-methylcatechol were used as substrates, the yellow fraction showed higher activity for pH 4.5–6.5, and the blue fraction showed higher activity for pH 7.0–8.0. When 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) was used as the substrate, both fractions showed maximum activity at optimum pH of 3.0–4.0. Conventionally, in research on blue laccase derived from lacquer, the non-blue fraction corresponding to the yellow fraction lower than pI 6 has been removed during the purification process and thus has not been analyzed. Our results indicated that yellow laccase was present in the non-blue components of lacquer and that it may play a role in urushiol polymerization with previously reported blue laccase.

Pyridine–Adenine Dinucleotide Transhydrogenase Activity in Cells Cultured from Rat Hepatoma

1972 ◽  
Vol 50 (5) ◽  
pp. 447-456 ◽  
Author(s):  
C. De Luca ◽  
R. P. Gioeli
Keyword(s):  
Phosphate Buffer ◽  
Pyridine Nucleotide ◽  
Maximum Activity ◽  
Ph Optimum ◽  
Apparent Lack ◽  
Minimal Deviation ◽  
Ph Range ◽  
Pyridine Nucleotide Transhydrogenase ◽  
Rat Hepatoma ◽  
Cells Cultured

Preparations from cells cultured from a minimal-deviation hepatoma in the rat exhibit pyridine nucleotide transhydrogenase (NAD(P)H: NAD(P) oxidoreductase, EC 1.6.1.1) activity. The pH optimum, its release by digitonin, and its apparent lack of dependence on steroids for activity tentatively classify it as a transhydrogenase of the type first described for animal tissue.Enzyme preparations from digitonin-treated homogenates were very unstable. The time necessary for the loss of one-half the activity was 16–18 h when the enzyme was stored at 5 °C; this was reduced to 4 h when storage was in polycarbonate tubes.The enzyme apparently transferred hydrogen directly and with equal ease from NADH to both the 3-acetyl-pyridine and thionicotinamide analogues of NAD. Half-saturation values for NAD and its acetylpyridine analogue were 0.99 × 10−5 M and 3.55 × 10−4 M, respectively. The enzyme exhibited its maximum activity in phosphate buffer at pH 5.8. It was inhibited by 50–60% over the pH range 7.0–8.5 in Tris buffer. This could be reversed by dithiothreitol; reversal was complete between pH 8.0 and 8.5.

Phenolic Wastewater Treatment by Microwave-Induced H2O2-Fe (III)-Cu (II)/γ-Al2O3 Catalytic Oxidation Process

2013 ◽  
Vol 777 ◽  
pp. 101-105
Author(s):  
Jie Zhang ◽  
Wei Qian Pan ◽  
Tong Zheng ◽  
Peng Wang
Keyword(s):  
Catalytic Oxidation ◽  
Oxidation Process ◽  
Synthetic Wastewater ◽  
Reaction Rate Constants ◽  
Toc Removal ◽  
First Order Kinetics ◽  
Phenolic Pollutants ◽  
Phenolic Wastewater ◽  
Ph Range ◽  
Induction Stage

To achieve efficient removal of phenolic pollutants in water, the catalyst of Fe (III)-Cu (II)/γ-Al2O3 was prepared. In the presence of Fe (III)-Cu (II)/γ-Al2O3, microwave-induced hydrogen peroxide (H2O2) catalytic oxidation process was conducted for the treatment of synthetic wastewater containing PNP, a representative of phenolic pollutants. Effectiveness of the process and factors influencing PNP removal were investigated and results showed microwave-induced H2O2-Fe (III)-Cu (II)/γ-Al2O3 process could achieve 99.41% PNP removal percentage, corresponding to 77.9% TOC removal in a given condition. The process remained effective in the 2-8 pH range with high reusability of Fe (III)-Cu (II)/γ-Al2O3 catalyst. The kinetics study showed microwave-induced H2O2-Fe (III)-Cu (II)/γ-Al2O3 process could be divided into microwave induction stage and catalytic oxidation stage, both of which fitted first-order kinetics, with reaction rate constants of 0.0453 min-1 and 4.7552 min-1 respectively.

Chemilumineszenz der SO2-Oxidation / Chemiluminescence of SO2-Oxidation

1978 ◽  
Vol 33 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Joachim Stauff ◽  
Wolfgang Jaeschke
Keyword(s):  
Aqueous Solutions ◽  
Spectral Region ◽  
Time Course ◽  
Light Emission ◽  
Analog Computer ◽  
Reaction Scheme ◽  
So2 Oxidation ◽  
Recombination Product ◽  
Electronically Excited ◽  
Ph Range

Abstract The reactions of diluted aqueous solutions of SO2 resp. HSO3-ions with MnO4-or Ce4+ ions in the pH range 1-4 produce chemiluminescence in the spectral region of 450-600 nm. Measurements of the time course of the light emission and their simulation on an analog computer led to a reaction scheme in which a recombination product of primarily formed HSO3 radicals -of a lifetime of about 1 second -appears as precursor of electronically excited SO2 molecules. The participation of singlet oxygen can be excluded because at least the reaction with Ce4+ ions proceeds also in the absence of oxygen.

Focusing of Proteins in a Horseshoe Microchannel

2008 ◽  
Author(s):  
Jaesool Shim ◽  
Prashanta Dutta ◽  
Cornelius F. Ivory
Keyword(s):  
Capillary Electrophoresis ◽  
Electric Field ◽  
Isoelectric Focusing ◽  
Ph Gradient ◽  
Complex Geometries ◽  
Electrokinetic Phenomena ◽  
Double Peaks ◽  
Zone Electrophoresis ◽  
Carrier Ampholytes ◽  
Ph Range

Ampholyte based isoelectric focusing (IEF) simulation was conducted to study dispersion of proteins in a horseshoe microchannel. Four model proteins (pls = 6.49, 7.1, 7.93 and 8.6) are focused in a 1 cm long horseshoe channel under an electric field of 300 V/cm. The pH gradient is formed in the presence of 25 biprotic carrier ampholytes (ΔpK = 3.0) within a pH range of 6 to 9. The proteins are focused at 380 sec in a nominal electric field of 300 V/cm. Our numerical results show that the band dispersions of a protein are large during the marching stage, but the dispersions are significantly reduced when the double peaks start to merge. This rearrangement of spreading band is very unique compared to linear electrokinetic phenomena (capillary electrophoresis, zone electrophoresis or electroosmosis) and is independent of channel position and channel shape. Hence, one can perform IEF in complex geometries without incorporating hyperturns.

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