scholarly journals Electroendosmotic liquid flows in various wide and narrow pH range isoelectric focusing gel prepared with IsoGel and Agarose IEF.

1987 ◽  
Vol 31 (6) ◽  
pp. 423-429
Author(s):  
Sadao Kobayashi ◽  
Eiji Yoshihara ◽  
Jun Suzuki
Keyword(s):  
Isoelectric Focusing ◽  
Ph Range ◽  
Liquid Flows ◽  
Agarose Ief

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.

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.

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.

Effects of androgens on bioactivity and immunoreactivity of pituitary FSH in GnRH antagonist-treated male rats

1990 ◽  
Vol 122 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Om P. Sharma ◽  
Shafiq A. Khan ◽  
Gerhard F. Weinbauer ◽  
Mohammed Arslan ◽  
Eberhard Nieschlag
Keyword(s):  
Isoelectric Focusing ◽  
Gnrh Antagonist ◽  
Molecular Composition ◽  
Male Rats ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Combined Administration ◽  
Ph Range ◽  
Fsh Bioactivity

Abstract The effects of androgens on the bioactivity and molecular composition of pituitary FSH were examined in intact and GnRH antagonist-suppressed male rats. Eight groups of adult Sprague-Dawley rats were subjected to the following treatments: antagonist (75 μg/day by osmotic minipumps; sc), testosterone-filled Silastic implants (3×5 cm, sc), dihydrotestosterone-filled Silastic implants (3×5 cm, sc), E2 benzoate (15 μg/day, sc), and combined administration of antagonist with either steroid for 3 weeks. At the end of the treatment period, pituitaries were dissected out and homogenised. FSH content was determined in the pituitary extracts by an in vitro bioassay and a radioimmunoassay. Individual pituitary extracts from rats treated with vehicle, testosterone and testosterone + antagonist were subjected to isoelectric-focusing on sucrose density gradients performed in the pH range from 3.5 to 7.0. Individual isoelectric-focusing fractions (100-120) were analysed for bioactive and immunoreactive FSH. Treatment with antagonist, E2 or antagonist + E2 caused a significant decrease in pituitary FSH, whereas testosterone and dihydrotesterone alone or in combination with antagonist prevented the decrease in pituitary FSH. The effects of all treatments on both bioactive and immunoreactive FSH were similar. Testosterone treatment not only maintained FSH synthesis but also altered the molecular composition of pituitary FSH. Following treatment with testosterone there was a shift of maximal FSH bioactivity to the more acidic pH range. On the other hand, less bioactivity was recovered than corresponding immunoreactivity in the higher pH region, resulting in significantly reduced ratios of bioactivity to immunoreactivity of FSH. No significant differences were found in the isoelectric-focusing profiles or bioactivity to immunoreactivity ratios of pituitary FSH in animals treated with testosterone alone or in combination with antagonist. The results demonstrate that testosterone not only maintained the synthesis of both bioactive and immunoreactive FSH in male rats, but also influences the molecular composition of pituitary FSH. These effects of testosterone on pituitary FSH appear not to be mediated through hypothalamic GnRH.

Isolation and partial purification of phytotoxins from liquid cultures of Leucostoma cincta and Leucostoma persoonii

1991 ◽  
Vol 69 (9) ◽  
pp. 1998-2003 ◽  
Author(s):  
A. M. Svircev ◽  
A. R. Biggs ◽  
N. W. Miles
Keyword(s):  
Isoelectric Focusing ◽  
Prunus Persica ◽  
Partial Purification ◽  
Liquid Cultures ◽  
Phytotoxic Activity ◽  
Stem Necrosis ◽  
Cold Acetone ◽  
Characterization Studies ◽  
Ph Range ◽  
Cytospora Canker

Phytotoxins from Leucostoma persoonii and Leucostoma cincta were isolated by sequential ultrafiltration of cell-free culture filtrates through a series of exclusion membranes. Phytotoxic activity, characterized by stem necrosis and leaf wilt, chlorosis, and necrosis, was evident when a cold acetone precipitate from the < 1000-Da fraction was tested in a peach shoot tip bioassay. Analytical polyacrylamide isoelectrofocusing of the < 1000-Da fraction in the pH range 3.5–6.0 identified two peptide bands at pH 4.0 and 6.0. Preparative granulated bed isoelectric focusing in the same pH range yielded two fractions with phytotoxic activity against peach shoots. Preliminary characterization studies indicate that the two fractions with toxin activity contain small polypeptides. Key words: Cytospora spp., cytospora canker, Prunus persica, peach.

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.

Fish Species Identification by Isoelectric Focusing: Sarcoplasmic Protein Polymorphism in Monkfish (Lophius americanus)

1981 ◽  
Vol 64 (1) ◽  
pp. 32-37
Author(s):  
Ronald C Lundstrom
Keyword(s):  
Species Identification ◽  
Isoelectric Focusing ◽  
Fish Species ◽  
Protein Pattern ◽  
Polyacrylamide Gel ◽  
Protein Patterns ◽  
Fish Species Identification ◽  
Sarcoplasmic Protein ◽  
Gel Isoelectric Focusing ◽  
Agarose Ief

Abstract Monkfish (Lophius americanus) sarcoplasmic protein patterns were found to be polymorphic with respect to separations using isoelectric focusing. Reproducible protein pattern variations were not detected using cellulose acetate or polyacrylamide gel disc electrophoresis. Monkfish sarcoplasmic proteins separated on pH 3.5-9.5 Ampholine PAGplates or on pH 2.5-9.0 agarose IEF gels yielded similar patterns showing 3 distinct, reproducible variations. On close examination, the pH 3.5-9.5 Ampholine PAGplate patterns could be further subdivided into 3 additional variations. A high resolution pH 3.5-5.0 agarose IEF gel was able to resolve a total of 10 different monkfish pattern variations in a sample of 24 individuals. A model was proposed suggesting the existence of 16 distinct variations in the monkfish sarcoplasmic protein pattern, based on the various combinations of 4 protein bands. In identifying samples of monkfish meat, it is necessary to compare the unknown pattern with the possible variant patterns to effect a reliable identification. On recommendation by the Associate Referee, the method for fish species identification based on polyacrylamide gel isoelectric focusing, 18.A01-18.A04, has been adopted official final action with no restrictions as to the species that may be identified.

scholarly journals One cell–one immunoglobin. Origin of limited heterogeneity of myeloma proteins

1970 ◽  
Vol 116 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Z. L. Awdeh ◽  
A. R. Williamson ◽  
Brigitte A. Askonas
Keyword(s):  
Isoelectric Focusing ◽  
Light Chain ◽  
Time Intervals ◽  
Myeloma Protein ◽  
Heavy Chains ◽  
Serum Component ◽  
Isoelectric Points ◽  
Ph Range ◽  
A Charge

Plasma-cell tumour 5563 forms a single molecular species of immunoglobulin IgG2a, i.e. one variant of heavy chain and one variant of light chain. The molecules formed are labile and undergo alterations in charge properties, which rapidly lead to heterogeneity of the myeloma protein after synthesis. The single immunoglobulin species originally formed is found only after the shortest time-intervals tested, i.e. 10min incubation. Two types of changes in charge properties take place: (1) The originally formed protein (component o) is converted via an intermediate o′ into the most basic form of 5563 myeloma protein found in serum (component a). Charge differences between these components are suppressed at pH8.9, but can be studied by chromatography at pH6.5 or by analysis of isoelectric points by isoelectric focusing in polyacrylamide gel. The conversion of components o and o′ into component a apparently commences soon after assembly of the molecules and proceeds to completion extracellularly. (2) The second type of charge difference that distinguishes components a, b, c and d is exhibited over the pH range 6.0–8.9, but not at acid pH, and has been studied by electrophoresis at pH8.9, by chromatography and by isoelectric focusing. Conversion of component a into components b, c, d and e is only partial so that all five components can be found at decreasing concentrations in serum. Both types of charge alteration can be effected in vitro in the presence of serum, with optimum pH8.0. None of the charge differences could be attributed to the secretion process, since a component with the same isoelectric point as component o was found in secreted myeloma protein (1h). We have found no evidence to support the idea that the first type of change from component o to component a is due to ring formation of N-terminal [14C]glutamine into pyrrolid-2-one-5-carboxylic acid; however, our findings do not exclude this process happening very rapidly to a precursor of component o, possibly the polypeptide chain during or immediately after synthesis. In studying this point we noted that not only the heavy chains but also the κ-type light chain of mouse 5563 myeloma protein have a blocked N-terminus.

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