The use of two-dimensional electrophoresis in the characterization of the water-soluble protein fraction of commercial flat fish species

The purpose of this study was to analyse the amino acid composition of otolith matrix protein, estimate the proportion of the water-soluble protein fraction, and analyse the effect of matrix composition on otolith visual appearance. Juvenile Atlantic cod (Gadus morhua) were reared under constant temperature and feeding conditions and sampled at the beginning and the end of the experiment. The amino acid composition was dominated by asparagine, glutamic acid, leucine, serine, and proline. A change in amino acid composition was observed with increasing temperature and time, caused by changing proportions of the water-soluble and -insoluble protein fractions. Feeding level had no effect. The relative content of water-soluble protein was linearly related to fish dry weight and temperature. Otolith opacity, defined as the percentage of incident light absorbed by an otolith section, did not differ significantly between experimental treatments. The soluble protein fraction had a positive, albeit insignificant, correlation with opacity. Using opacity and otolith volume, deposited total otolith protein content was estimated with an R2 of 0.91, where otolith volume alone explained 83% of the observed variation.

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Capillary HPLC–ICP MS mapping of selenocompounds in spots obtained from the 2-D gel electrophoresis of the water-soluble protein fraction of selenized yeast

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-006-0482-6 ◽

2006 ◽

Vol 385 (5) ◽

pp. 948-953 ◽

Cited By ~ 18

Author(s):

Laure Tastet ◽

Dirk Schaumlöffel ◽

Brice Bouyssiere ◽

Ryszard Lobinski

Keyword(s):

Gel Electrophoresis ◽

Soluble Protein ◽

Protein Fraction ◽

Water Soluble ◽

Soluble Protein Fraction ◽

Water Soluble Protein ◽

Icp Ms ◽

Capillary Hplc ◽

Selenized Yeast

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ANTIBODY STUDIES IN RABBIT ENCEPHALOMYELITIS INDUCED BY A WATER-SOLUBLE PROTEIN FRACTION OF RABBIT CORD

Journal of Experimental Medicine ◽

10.1084/jem.116.6.807 ◽

1962 ◽

Vol 116 (6) ◽

pp. 807-825 ◽

Cited By ~ 39

Author(s):

Robert F. Kibler ◽

Arthur E. Barnes

Keyword(s):

Soluble Protein ◽

Protein Fraction ◽

Nervous Tissue ◽

Serum Antibody ◽

Paper Electrophoresis ◽

Water Soluble ◽

Soluble Protein Fraction ◽

Water Soluble Protein ◽

Antigen Antibody ◽

Suitable Technique

A water-soluble protein fraction of nervous tissue was prepared by extraction of rabbit spinal cord with sodium citrate at pH 4.3. Characterization by nitrogen content and paper electrophoresis showed it to be a mixture of basic proteins. This extract demonstrated encephalitogenic activity when injected into rabbits. The most suitable technique for the measurement of serum antibody to the rabbit cord antigen proved to be the precipitation of antigen-antibody complexes by 40 per cent saturated ammonium sulfate. Antibody could not be demonstrated by the techniques of complement fixation, quantitative precipitation, and Ouchterlony plates. The early appearance of circulating antibody occurred almost exclusively in rabbits that subsequently developed EAE. Specificity of the antibodies for nervous tissue was demonstrated by appropriate blocking and adsorption experiments.

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