Biomedical subjects
Publications and source records attributed to E Fleissner.
Detergent treatment releases from both avian and mammalian oncornaviruses a structure containing the viral RNA and a major arginine-rich protein, as well as reverse transcriptase activity.
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Proteins of leukemia and sarcoma viruses from the chicken, mouse, hamster, and cat were analyzed by gel filtration in guanidine hydrochloride. The mammalian viruses were found to contain six major proteins, whereas the avian viruses contained seven proteins. Proteins of viruses from different mammalian species had the same molecular weights which also closely resembled the molecular weights of the six equivalent avian viral proteins. These results defined a basic similarity in protein composition for the C-type viruses of avian and mammalian origin. The two glyco-proteins of murine leukemia virus were identified immunologically as constituents of the viral membrane. Antisera prepared against other proteins distinguished individual internal viral antigens in immunodiffusion tests and also reacted in immunofluorescence with cytoplasmic components of infected cells. Antisera which reacted with the major internal viral proteins did not contain antibodies inhibitory to the viral reverse transcriptase.
Gel filtration of avian tumor virus proteins in 6 m guanidine hydrochloride clearly resolved seven major protein species. The antigenic activity of these proteins was recovered in good yield after removal of the denaturing solvent, permitting a correlation of specific polypeptides with the principal antigens of the virion. Two of the proteins, of molecular weights 70,000 and 32,000, contain carbohydrate and are situated on the viral membrane, as shown by their being accessible in the intact virus to specific antibodies. Four proteins, with molecular weights (in guanidine) of 27,000, 19,000, 15,000, and 12,000, have different group-specific (gs) antigens and are enclosed within the viral membrane. The smallest protein, with a molecular weight of 10,000, has not previously been described; it is not detectable with antisera and possesses a mobility identical to that of one gs protein when subjected to electrophoresis in polyacrylamide gels in the presence of sodium dodecyl sulfate. Of the proteins lacking carbohydrate, three are present in the virion in a molecular ratio of 2:2:1, and the two others, present in almost equal amount, are rich in lysine and arginine.
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Virus-specific antigens were studied in hamster cells transformed by Rous sarcoma virus (RSV). Antigens were localized in the cytoplasm, as demonstrated by fluorescent antibody staining of fixed cells as well as by complement fixation (CF) following subcellular fractionation. Cytoplasmic extracts were analyzed by velocity and isopycnic centrifugation. CF antigens were found in a soluble form and in association with membranes and polyribosomes. Isolated plasma membranes had no CF antigen. Both soluble and particulate fractions with CF activity contained the same antigenic determinants by Ouchterlony analysis. These antigenic determinants were identical to those released by ether treatment of RSV.
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