Fish proteins

CARP MYOGENS OF WHITE AND RED MUSCLES. GROSS ISOLATION ON SEPHADEX COLUMNS OF THE LOW-MOLECULAR-WEIGHT COMPONENTS AND EXAMINATION OF THEIR PARTICIPATION IN ANAEROBIC GLYCOGENOLYSIS

1. The combined low-molecular-weight protein components of the myogens from carp white and red muscles [about 30% (w/w) of the myogen proteins] have been isolated by gel filtration on Sephadex G-75 columns. 2. The presence in this fraction from myogen of white muscle of the three main electrophoretic components previously isolated has been confirmed, and the low molecular weight of the fourth component has been definitely established. 3. The exclusive presence of this fourth component in the myogen of red muscle, apart from myoglobin, has also been demonstrated. 4. Glycogenolysis experiments in vitro have shown that the low-molecular-weight protein fraction from carp myogen does not contain enzymes from the Embden-Meyerhof chain.

CARP MYOGENS OF WHITE AND RED MUSCLES. GENERAL COMPOSITION AND ISOLATION OF LOW-MOLECULAR-WEIGHT COMPONENTS OF ABNORMAL AMINO ACID COMPOSITION

1. The general composition of the carp myogens of white and red muscles was examined by electrophoresis and ultracentrifugation. 2. Eight and nine peaks were found in the electrophoretic analysis at pH7.3 and I0.075 of white and red muscle respectively. Lowering of the pH to 5 or 6 did not increase the number of peaks. The electrophoretic pattern of white-muscle myogen was remarkably different from that of red-muscle myogen, though ultracentrifugal analyses of the both types of myogen gave similar diagrams, in which about one-third of the total myogen sedimented slowly. 3. The pH-mobility curves of the myogen of white muscle indicated that the net charges of the components 2, 3 and 5 vary only slightly within the pH range 7.3-5.4, suggesting that their histidine content is very low. 4. The slow-sedimenting fraction of white-muscle myogen was isolated in fairly good yield by ammonium sulphate fractionation, by taking advantage of their high salting-out range, and the fraction was shown to be composed mainly of components 2, 3 and 5. 5. The same method of fractionation was applied to red-muscle myogen and the absence of the three components was confirmed. These results bring to light a new difference between the two types of fish muscle.

Biochemistry of the autolytic processes in Antarctic krill post mortem. Autoproteolysis

1. Autoproteolysis post mortem was examined at 0 degree C by following the changes in the major classes of krill (Euphausia superba and Euphausia crystallorophias) proteins and by liberation of peptides and free amino acids, and was based on experiments conducted on board expedition vessels in the Antarctic. 2. Primarily salt-soluble proteins were broken down during the first week of incubation, whereas water-soluble and insoluble proteins were degraded to a much smaller extent. The enzymes responsible for the hydrolysis presumably originate primarily from the digestive apparatus of the krill. 3. In general, the individual amino acids were released at rates corresponding to their relative occurrence in the bulk protein of the krill. Alanine was liberated in larger amounts than would be expected from the composition of the krill protein, and was evidently formed also by reactions other than proteolysis. Glutamic acid, and certain amino acids which presumably occur with high frequency adjacent to glumatic acid residues in the krill protein, were liberated only to a limited extent, and accumulated in smaller peptides. 4. During proteolysis, arginine seemed to be converted to some degree into ornithine, and on prolonged incubation conversion of arginine and lysine into their corresponding decarboxylation products, agmatine and cadaverine, appeared to take place.

Estudo eletroforético de proteínas de músculo esquelético de Micropogonias furnieri (Desmarest, 1823) da costa SE-S do Brasil: 1. Considerações técnicas

No presente trabalho, foram analisados os efeitos de diferentes posições de coleta e de diferentes períodos de preservação das amostras a -15ºC sobre os eletroferogramas de proteínas gerais do músculo esquelético de Micropogonias furnieri, e as condições para extração e a eletroforese das proteínas foram estabelecidas . Foram comparados o poder de extração e de preservação de 4 soluções: água destilada; cloreto de sódio 0,9%; tampão fosfato pH 7,5 µ=0,05 (Connell, 1953); glicerol-EDTA-Tris pH 8,7 (Scopes, 1968). As condições de eletroforese foram investigadas, utilizando-se membranas de acetato de celulose com seis diferentes sistemas de tampões e gel de amido com três diferentes sistemas de tampão. As amostras coletadas de diferentes posições não apresentaram diferenças no número nem na posição relativa das bandas nos eletroferogramas. Foram anotadas alterações nos eletroferogramas conforme o período de preservação das amostras. A solução glicerol-EDTA-Tris pH 8,7 apresentou o maior poder de extração e de preservação. Nos sistemas de tampão testados, o número máximo de 9 bandas foi obtido, tanto em membrana de acetato de celulose como em gel de amido. Melhor separação das proteínas em membrana de acetato de celulose foi obtida com tampão Tris-glicina pH 8,3 (Tris 0,0495M, glicina 0,3836M), e em gel de amido, com tampão do gel constituído por Tris, EDTA e ácido bórico, de pH 8,6 (Huehns, 1968) e tampão da cuba constituído por ácido bórico e hidróxido de sódio (Smithies, 1955).

Methods for starch-gel electrophoresis of sarcoplasmic proteins. An investigation of the relative mobilities of the glycolytic enzymes from the muscles of a variety of species

1. Details of an improved method for starch-gel electrophoresis of water-soluble muscle proteins are given. 2. Methods are described for detecting enzyme activities on the starch gel after electrophoresis, by using pieces of filter paper. 3. Compositions of incubation mixtures suitable for detecting any of the enzymes of glycolysis, and certain other enzymes, are given. 4. A comparison of the various enzymes in extracts of several muscles from one rabbit was made; most differences are quantitative only. 5. A detailed comparison of the mobilities of various enzymes in extracts of muscles from a wide variety of species was made. Each species was found to have a characteristic pattern of proteins on the starch gel, and the mobilities of individual enzymes varied considerably. 6. Potential uses and extensions of the methods are discussed.

MUSCLE PROTEINS OF PACIFIC SALMON (ONCORHYNCHUS): II. AN INVESTIGATION OF MUSCLE PROTEIN AND OTHER SUBSTANCES SOLUBLE IN SALT SOLUTIONS OF LOW IONIC STRENGTH BY COLUMN CHROMATOGRAPHY

The muscle myogens and other components of the spring salmon (O. tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), and sockeye salmon (O. nerka), as well as the lingcod (Ophiodon elongatus), were separated by the use of diethylaminoethyl (DEAE) cellulose columns. Significant amounts of slowly dialyzable inosine and inosinic acid which may lead to spurious peaks in moving-boundary electrophoretic separations have been shown to be present in the muscle myogen preparations. The basic differences in the muscle myogen components of the Pacific salmon and the lingcod are compared.

Species Differentiation in Fish by Electrophoretic Analysis of Skeletal Muscle Proteins

Extracts of skeletal muscle protein from ten species of the fresh-water sunfish family were examined by the electrophoretic technique, and the resulting patterns showed characteristic specificity in each instance. Usually three major components of greater mobility were accompanied by slower moving minor components. No uniformity of mobility or of proportion of protein was evident. Thus patterns that "fingerprint" the species are evident.

Studies on the protein of fish skeletal muscle. 4. Ultracentrifugal analysis of codling extracts*

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