Protein Synthesis in the Myocardiopathy and Muscular Dystrophy of the Syrian Hamster

1971 ◽  
Vol 40 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Amanda Lochner ◽  
Anke Brink ◽  
A. J. Brink
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Muscular Dystrophy ◽  
Syrian Hamster ◽  
Soluble Protein ◽  
Protein Fraction ◽  
Age Groups ◽  
Biceps Femoris ◽  
Soluble Protein Fraction

1. Incorporation in vitro of l-[4,5-3H]leucine and l-[U-14C]lysine into a soluble protein fraction and into actomyosin of hearts, diaphragms and biceps femoris of an inbred strain of Syrian hamsters suffering from a hereditary myocardiopathy and muscular dystrophy was studied. 2. Incorporation of both amino acids was normal in myopathic hearts from hamsters aged 60–90 days but significantly elevated at 180–240 days of age. Their incorporation was higher in the myopathic diaphragm and biceps femoris of both age groups.

scholarly journals Effects of HSPA8, an evolutionarily conserved oviductal protein, on boar and bull spermatozoa

Reproduction ◽  
2009 ◽  
Vol 137 (2) ◽  
pp. 191-203 ◽  
Author(s):  
Roslyn M A Elliott ◽  
Rhiannon E Lloyd ◽  
Alireza Fazeli ◽  
Edita Sostaric ◽  
A Stephen Georgiou ◽  
...  
Keyword(s):  
Soluble Protein ◽  
Protein Fraction ◽  
Mammalian Species ◽  
Surface Proteins ◽  
Apical Plasma Membrane ◽  
Enhancement Effect ◽  
Soluble Protein Fraction ◽  
Sperm Survival ◽  
Pre Treatment

Previous studies have shown that a soluble protein fraction derived from preparations of apical plasma membrane (APM) of the oviductal epithelium enhances the in vitro survival of mammalian spermatozoa. Here, we show that the survival enhancing property of the soluble protein fraction seems to depend significantly upon heat shock 70 kDa protein 8 (HSPA8 previously known as HSPA10). The following findings in the present study enabled us to draw this conclusion: first, using proteomic analysis, we identified a subset of 70 kDa oviductal surface proteins that bound to spermatozoa, one of which was HSPA8. Second, pre-treatment of the soluble protein fraction with anti-HSPA8 antibody reduced the 24 h (at 39 °C) sperm survival enhancement effect normally induced by the presence of 200 μg/ml soluble APM proteins. Third, complementary experiments showed that substituting the soluble protein fraction with bovine recombinant HSPA8 (0.5–2 μg/ml) also elicited the sperm survival effect. Finally, we also tested the effect of bovine recombinant HSPA8 on bull spermatozoa and found similar, dose-responsive, sperm survival promoting effects. The conserved nature of HSPA8 between mammalian species suggests that this protein may represent a common biological mechanism for the maintenance of sperm survival in the oviduct.

The formation of sulfenyl iodides as intermediates during the in vitro iodination of tyrosine by calf thyroid homogenates

1968 ◽  
Vol 46 (12) ◽  
pp. 1433-1441 ◽  
Author(s):  
David M. Fawcett
Keyword(s):  
Optical Density ◽  
Soluble Protein ◽  
Protein Fraction ◽  
Significant Proportion ◽  
Sulfenyl Chloride ◽  
Soluble Protein Fraction ◽  
The Stability ◽  
Excess Iodide ◽  
Active Preparation

Following dialysis against chlorinated water, the soluble protein fraction of calf thyroid homogenates readily iodinated tyrosine when supplemented with iodide at 37 °C. Addition of iodide to an active preparation also resulted in a rapid increase in optical density at 355 mμ, characteristic of sulfenyl iodide formation. The thyroidal sulfenyl iodide was stable for long periods at 5 °C, but at 20 °C or 37 °C it disappeared with the formation of monoiodotyrosine (MIT) and diiodotyrosine (DIT). The decomposition of the reactive thyroidal species in the presence of 2-mercaptoethanol was characteristic of the behaviour of sulfenyl iodides but not I3−. Excess iodide increased the stability of the sulfenyl iodide but inhibited the iodination of tyrosine. Thiourea inhibited both sulfenyl iodide formation and iodination.Evidence is presented that the chlorine activation of thyroid protein involved sulfenyl chloride formation. During dialysis of thyroid protein against 36Cl-chlorinated water a significant proportion of the 36Cl became bound to protein. Protein-bound and nonprotein-bound 36Cl were separated by filtration through Sephadex G-50. Incubation of the protein-bound fraction with 131I-iodide resulted in displacement of 36Cl by 131I and the formation of 131I-MIT and 131I-DIT. These studies support the hypothesis that thyroidal iodotyrosine formation may involve sulfenyl iodide intermediates.

scholarly journals Identification in skeletal muscle of a distinct extracellular pool of amino acids, and its role in protein synthesis

1971 ◽  
Vol 121 (5) ◽  
pp. 817-827 ◽  
Author(s):  
R. C. Hider ◽  
E. B. Fern ◽  
D. R. London
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Incubation Medium ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Longus Muscle ◽  
Kinetics Of

1. The kinetics of radioactive labelling of extra- and intra-cellular amino acid pools and protein of the extensor digitorum longus muscle were studied after incubations with radioactive amino acids in vitro. 2. The results indicated that an extracellular pool could be defined, the contents of which were different from those of the incubation medium. 3. It was concluded that amino acids from the extracellular pool, as defined in this study, were incorporated directly into protein.

Effect of Cycloheximide on In Vitro and In Vivo Protein Synthesis by Certain Tissues of Rats and Pigeons with Special Reference to Muscle

1973 ◽  
Vol 51 (12) ◽  
pp. 933-941 ◽  
Author(s):  
Njanoor Narayanan ◽  
Jacob Eapen
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Amino Acid Incorporation ◽  
Contrast Administration ◽  
Acid Incorporation ◽  
Tissue Homogenates

The effect of cycloheximide in vitro and in vivo on the incorporation of labelled amino acids into protein by muscles, liver, kidneys, and brain of rats and pigeons was studied. In vitro incorporation of amino acids into protein by muscle microsomes, myofibrils, and myofibrillar ribosomes was not affected by cycloheximide. In contrast, administration of the antibiotic into intact animals at a concentration of 1 mg/kg body weight resulted in considerable inhibition of amino acid incorporation into protein by muscles, liver, kidneys, and brain. This inhibition was observed in all the subcellular fractions of these tissues during a period of 10–40 min after the administration of the precursor. Tissue homogenates derived from in vivo cycloheximide-treated animals did not show significant alteration in in vitro amino acid incorporation with the exception of brain, which showed a small but significant enhancement.

scholarly journals The rate-limiting step of protein synthesis in vivo and in vitro and the distribution of growing peptides between the puromycinlabile and puromycin-non-labile sites on polyribosomes

1971 ◽  
Vol 122 (3) ◽  
pp. 267-276 ◽  
Author(s):  
D. C. N. Earl ◽  
Susan T. Hindley
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Donor Site ◽  
Peptide Bond ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Donor And Acceptor ◽  
Rate Limiting

1. At 3 min after an intravenous injection of radioactive amino acids into the rat, the bulk of radioactivity associated with liver polyribosomes can be interpreted as growing peptides. 2. In an attempt to identify the rate-limiting step of protein synthesis in vivo and in vitro, use was made of the action of puromycin at 0°C, in releasing growing peptides only from the donor site, to study the distribution of growing peptides between the donor and acceptor sites. 3. Evidence is presented that all growing peptides in a population of liver polyribosomes labelled in vivo are similarly distributed between the donor and acceptor sites, and that the proportion released by puromycin is not an artifact of methodology. 4. The proportion released by puromycin is about 50% for both liver and muscle polyribosomes labelled in vivo, suggesting that neither the availability nor binding of aminoacyl-tRNA nor peptide bond synthesis nor translocation can limit the rate of protein synthesis in vivo. Attempts to alter this by starvation, hypophysectomy, growth hormone, alloxan, insulin and partial hepatectomy were unsuccessful. 5. Growing peptides on liver polyribosomes labelled in a cell-free system in vitro or by incubating hemidiaphragms in vitro were largely in the donor site, suggesting that either the availability or binding of aminoacyl-tRNA, or peptide bond synthesis, must be rate limiting in vitro and that the rate-limiting step differs from that in vivo. 6. Neither in vivo nor in the hemidiaphragm system in vitro was a correlation found between the proportion of growing peptides in the donor site and changes in the rate of incorporation of radioactivity into protein. This could indicate that the intracellular concentration of amino acids or aminoacyl-tRNA limits the rate of protein synthesis and that the increased incorporation results from a rise to a higher but still suboptimum concentration.

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

scholarly journals Amino acid regulation of synthesis of ribonucleic acid and protein in the liver of rats

1971 ◽  
Vol 124 (2) ◽  
pp. 385-392 ◽  
Author(s):  
R. W. Wannemacher ◽  
C. F. Wannemacher ◽  
M. B. Yatvin
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Cellular Protein ◽  
Deficient Diet ◽  
Cellular Protein Content ◽  
Regulate Protein

Weanling (23-day-old) rats were fed on either a low-protein diet (6% casein) or a diet containing an adequate amount of protein (18% casein) for 28 days. Hepatic cells from animals fed on the deficient diet were characterized by markedly lower concentrations of protein and RNA in all cellular fractions as compared with cells from control rats. The bound rRNA fraction was decreased to the greatest degree, whereas the free ribosomal concentrations were only slightly less than in control animals. A good correlation was observed between the rate of hepatic protein synthesis in vivo and the cellular protein content of the liver. Rates of protein synthesis both in vivo and in vitro were directly correlated with the hepatic concentration of individual free amino acids that are essential for protein synthesis. The decreased protein-synthetic ability of the ribosomes from the liver of protein-deprived rats was related to a decrease in the number of active ribosomes and heavy polyribosomes. The lower ribosomal content of the hepatocytes was correlated with the decreased concentration of essential free amino acids. In the protein-deprived rats, the rate of accumulation of newly synthesized cytoplasmic rRNA was markedly decreased compared with control animals. From these results it was concluded that amino acids regulate protein synthesis (1) by affecting the number of ribosomes that actively synthesize protein and (2) by inhibiting the rate of synthesis of new ribosomes. Both of these processes may involve the synthesis of proteins with a rapid rate of turnover.

Sign in / Sign up

Export Citation Format

Share Document