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E M Kreps

Publications and source records attributed to E M Kreps.

11 recordsLinked to original sources
PubMed1976

[Conditions of spontaneous gelatinization of sarcoplasmic proteins].

Ca2+ ions at low concentration (10(-4)-10(-5) M) when added to ultracentrifugates of sarcoplasmic proteins with minimal content of sarcoplasmic reticulum fragments completely prevent protein gelatinization or gels, formed in these conditions, quickly dilute. Ca2+ ions at the concentration of 10(-3) M prevented in these conditions gelatinization in all the cases studied. Strong gels of sarcoplasmic proteins are formed afterwards in weak acid (pH 6.1-6.75), neutral (pH 7.0) and weak alkaline (pH 7.25-7.45 and higher) media. It is suggested that gelatinization of sarcoplasmic proteins is closely related with the development of plastic tonus, obturatory muscle function and viscous after-effect.

Animals↗
PubMedDate not supplied

[Brain lipid biochemistry of the sturgeons Acipenseridae].

Brain lipids of 4 species of sturgeons-Acipenser güldenstädti, A. stellatus, A. ruthenus and Huso huso-have been investigated. In whole brain homogenates the content of the basic phospholipid families, their fatty acid composition as well as the content of glycosphingolipids-gangliosides, cerebrosides and sulfatides were studied. The quantitative relations between different molecular ganglioside fractions and their fatty acid composition, as well as the relative content of hydroxycerebrosides and cerebrosides with normal fatty acids were determined. The brain lipids of Acipenseridae were compared to previously obtained data on the brain of Elasmobranch and Teleost fishes. The brain lipid pattern of the four sturgeon species is very similar, but it differs greatly from that of Elasmobranch and of Teleostean brain, being in some respect more like the type of bony fish brain, in others the kind of brain of sharks and rays, and frequently considerably differing from both these types. The conspicous peculiarity in the content and molecular characteristics of the brain lipids of Acipenseridae compels us to agree with the opinion expressed by the late A.N. Belozerski and his coworkers [26, 27], based on a detailed study of fish DNA nucleotides, that the Ganoid fish are to be regarded as an independent class.

Animals↗
PubMedDate not supplied

[Sodium reabsorption and the membrane systems of vertebrate kidneys].

Sodium reabsorption is low in coldblooded animals (the lamprey Lampetra fluviatilis, red salmon Oncorhynchus nerka, carp Cyprinus carpio, frog Rana temporaria, tortoise Agryonemis horsfieldi) being much higher in warmblooded ones (chicken, pigeon, rat). High level of Na transport in warmblooded animals is paralleled by high activity of succinate dehydrogenase as compared with the activity of Na,K-ATPase. The content of monoenoic fatty acids in the glycerophosphatides from frog and tortoise kidneys is higher than that from pigeon and rat ones.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Brain lipids of a mammoth, Elephas primigenius, which died more than 40,000 years ago].

Studies have been made on the brain lipids of the 6--7-month mammoth which remained in the eternal ice for more than 40.000 years. Thin layer chromatography of chloroformmethanol extract of the brain lipids shows that all glycerophospholipids in the brain were destroyed. On the contrary, sphingophospholipid sphingomyelin yielded the evident spot which was identified by specific reactions and by comparison with sphingomyelin from the brain of rat. Sphingomyelin content was evaluated. Using gas-liquid chromatography, fatty acid composition of sphingomyelin was investigated. It was found to be close to that in contemporary mammals. Other shingolipids -- cerebrosides, sulfatides, gangliosides -- persisted (probably, only partially) and were studied quantitatively. Relative content of cerebrosides with normal fatty acids and hydrooxyacids was determined. Studies were also made on fatty acid composition of cerebrosides, sulfatides and gangliosides, as well as on the composition of spingosine bases of gangliosides. Free cholesterol was found in the brain of the mammoth. Other sterols were not detected. With respect to quantitative evaluation of the preserved lipids, it should be mentioned that on the one hand, the brain underwent dehydration which increased lipid content per a unit of "wet" weight, whereas on the other one lipids were partially degraded, this process decreasing their content.

Animals↗