The Separation of Tritiated Amino Acids via Liquidchromatography

1991 ◽  
Vol 27 (5) ◽  
pp. 264-265
Author(s):  
St. Noll ◽  
E. Mittag ◽  
B. Groβe
Keyword(s):  
Amino Acids ◽  
Tritiated Amino Acids

scholarly journals SYNTHESIS AND STORAGE OF MICROTUBULE PROTEINS BY SEA URCHIN EMBRYOS

1971 ◽  
Vol 50 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Rudolf A. Raff ◽  
Gerald Greenhouse ◽  
Kenneth W. Gross ◽  
Paul R. Gross
Keyword(s):  
Amino Acids ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Binding Activity ◽  
Total Soluble Protein ◽  
Cell Stage ◽  
Lytechinus Pictus ◽  
Sea Urchin Embryos ◽  
Tritiated Amino Acids ◽  
Vinblastine Sulfate

Studies employing colchicine binding, precipitation with vinblastine sulfate, and acrylamide gel electrophoresis confirm earlier proposals that Arbacia punctulata and Lytechinus pictus eggs and embryos contain a store of microtubule proteins. Treatment of 150,000 g supernatants from sea urchin homogenates with vinblastine sulfate precipitates about 5% of the total soluble protein, and 75% of the colchicine-binding activity. Electrophoretic examination of the precipitate reveals two very prominent bands. These have migration rates identical to those of the A and B microtubule proteins of cilia. These proteins can be made radioactive at the 16 cell stage and at hatching by pulse labeling with tritiated amino acids. By labeling for 1 hr with leucine-3H in early cleavage, then culturing embryos in the presence of unlabeled leucine, removal of newly synthesized microtubule proteins from the soluble pool can be demonstrated. Incorporation of labeled amino acids into microtubule proteins is not affected by culturing embryos continuously in 20 µg/ml of actinomycin D. Microtubule proteins appear, therefore, to be synthesized on "maternal" messenger RNA. This provides the first protein encoded by stored or "masked" mRNA in sea urchin embryos to be identified.

scholarly journals FINE STRUCTURAL AND RADIOAUTOGRAPHIC OBSERVATIONS ON DENSE PERINUCLEAR CYTOPLASMIC MATERIAL IN TADPOLE OOCYTES

1971 ◽  
Vol 49 (1) ◽  
pp. 90-108 ◽  
Author(s):  
E. M. Eddy ◽  
Susumu Ito
Keyword(s):  
Amino Acids ◽  
Nucleic Acids ◽  
Fibrous Material ◽  
Actinomycin D ◽  
Cytoplasmic Material ◽  
Germ Cell Differentiation ◽  
Dense Bodies ◽  
Perinuclear Cytoplasm ◽  
Tritiated Amino Acids ◽  
Silver Grains

Dense fibrous material is first seen in association with mitochondria in tadpole oogonia but is most prominent in oocytes during the extended first meiotic prophase when it aggregates into dense bodies in the perinuclear cytoplasm. The origin of this material has been attributed to 350-A nuclear granules which form cytoplasmic streamers of fibrous material upon passage through nuclear pores. This has commonly been interpreted as the transfer of ribonucleoprotein to the cytoplasm for storage. However, cytochemical reactions for nucleic acids have indicated an absence of detectable RNA in this dense material, and the results of radioautographic studies with labeled uridine, thymidine, or actinomycin D argue against the presence of nucleic acids. When sites of incorporation of tritiated amino acids were radioautographically localized, an appreciable number of silver grains were present over the dense bodies. Uptake of certain amino acids occurs fairly promptly but the degree of labeling levels off after about 6 hr, suggesting a rapid turnover of the material in the dense bodies. Attention is drawn to the similarity of the dense bodies to structures present in germ cells of a number of other species, and possible functions of the dense bodies in germ cell differentiation are considered.

Enzymatic preparation of α- and β-deuterated or tritiated amino acids with l-methionine γ-lyase

1982 ◽  
Vol 119 (2) ◽  
pp. 281-285 ◽  
Author(s):  
Nobuyoshi Esaki ◽  
Seiji Sawada ◽  
Hidehiko Tanaka ◽  
Kenji Soda
Keyword(s):  
Amino Acids ◽  
Enzymatic Preparation ◽  
Tritiated Amino Acids

scholarly journals THE NATURE OF HYPOTHALAMO-NEUROHYPOPHYSEAL NEUROSECRETION IN THE RAT

1974 ◽  
Vol 60 (3) ◽  
pp. 554-570 ◽  
Author(s):  
Christine Kent ◽  
M. A. Williams
Keyword(s):  
Amino Acids ◽  
Electron Microscope ◽  
Great Majority ◽  
Time Of Arrival ◽  
Neural Lobe ◽  
Ether Anesthesia ◽  
Light Microscope Level ◽  
Dense Cores ◽  
Intraventricular Injections ◽  
Tritiated Amino Acids

The nature of hypothalamo-neurohypophyseal neurosecretion was examined in the rat by means of intraventricular injections of tritiated amino acids. Quantitation of autoradiographs was used at the light microscope level to study the sites of synthesis of proteins and their time of arrival in the neural lobe. Electron microscope autoradiographs were used to study the labeling of neural lobe tissue. It was concluded that the great majority of the labeled material was translocated inside dense-cored granules and was probably composed mostly of neurophysins. The effect of ether anesthesia was also examined. It was found to remove the dense cores from about 20% of the granules in the neural lobe tissue, a process accompanied by the loss of most of their labeled material. The mechanism of the ether effect is discussed and compared to the normal secretion process.

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