Open AccessStructural Characteristics of Some Murine RNA Tumor Viruses Studied by Lactoperoxidase Iodination
Author(s) -
Owen N. Witte,
Irving L. Weissman,
Henry S. Kaplan
Publication year - 1973
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.70.1.36
Subject(s) - lactoperoxidase , murine leukemia virus , enzyme , polyacrylamide gel electrophoresis , virus , gel electrophoresis , biochemistry , microbiology and biotechnology , chemistry , biology , tumor virus , rna , virology , gene , peroxidase
Iodination by the noninvasive enzymatic lactoperoxidase technique has been used to study the enzyme-accessible and enzyme-inaccessible proteins of three oncorna viruses (radiation leukemia virus, Moloney leukemia virus, and mouse mammary tumor virus). The number and relative molecular weight of proteins associated with virion preparations purified on sucrose gradients were characterized by scans of Coomassie blue-stained bands after dodecyl sulfate-polyacrylamide gel electrophoresis. Gel scans from the leukemia viruses are similar, each showing six distinct major protein bands on stained gels. The mammary tumor virus proteins by this analysis are not similar to those of the leukemia viruses. Enzymatic iodination of intact virion preparations led to the solitary labeling of one of the major proteins of each virus-the 80,000-dalton protein of the leukemia viruses and the 52,500-dalton protein of the mammary tumor virus. These are tentatively positioned as surface (enzyme-accessible) moieties in the virions. Disruption of each virus with a nonionic nonionic detergent before enzymatic iodination led to the labeling of the remaining stainable bands. The four lower molecular weight bands of the leukemia viruses are tentatively positioned as internal (enzyme-inaccessible) components.