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Biomedical subjects

E L Kuff

Publications and source records attributed to E L Kuff.

At least 73 records · Page 4Linked to original sources
PubMed1974

Structural proteins of intracisternal A-particles: possible repetitive sequences.

Peptide maps of tryptic digests of the structural proteins from inner shells of intracisternal A-particles have shown common peptides for all the proteins. The terminal amino group of the three different structural proteins was identified as arginine. The major protein revealed approximately half the number of peptides expected from the amino acid composition. Since evidence for a cross-link bond has not been found, the main structural protein may be a single polypeptide chain containing a total or partial duplication of sequence.

Amino Acid Sequence↗
PubMed1973

Structural organization of murine intracisternal A particles.

Isolated murine intracisternal A particles have a distinctive set of structural properties as compared to the recognized oncogenic ribonucleic acid tumor viruses. A particles consist of two closely approximated concentric shells. The outer shell is largely, but not entirely, susceptible to treatment with detergents such as deoxycholate and Triton X-100. The inner shell is resistant to these agents and is stabilized against solubilization by sodium dodecyl sulfate as a result of disulfide bonding between its constituent proteins. The major A particle structural protein (molecular weight approximately 70,000) is contained in the inner shell. A protein component with a molecular weight of about 80,000 may be preferentially concentrated in sites of firm attachment between the inner and outer shells.

Animals↗
PubMed1972

Some structural and antigenic properties of intracisternal A particles occurring in mouse tumors (complement fixation-immunodiffusion-neuroblastoma-plasma-cell tumor).

Intracisternal A-particles were isolated from three different myeloma lines in BALB/c mice and from cultured neuroblastoma cells of A/J origin. All preparations contained a major structural protein with an apparent molecular weight near 70,000 as estimated by electrophoretic mobility in sodium dodecyl sulfate-containing polyacrylamide gels. Solubilization of this component by sodium dodecyl sulfate was dependent on prior or concomitant treatment with sulfhydryl compounds. The size distribution of A-particle proteins was markedly different from that observed for extracellular murine leukemia and mammary tumor viruses. Rabbit antiserum was developed that reacted with the major A-particle protein in both complement fixation and immunodiffusion assays. The antigen was detected in isolated neuroblastoma A-particles, in cytoplasmic membrane fractions prepared from various mouse tumors known to contain intracisternal particles, but not in preparations from normal mouse cells, in samples of leukemia and mammary tumor virus, or in JLS-V9 cells infected with Rauscher leukemia virus. Conversely, isolated A-particles did not react in complement fixation or immunodiffusion assays with antisera against leukemia virus antigens.

Animals↗
PubMed1972

A novel DNA polymerase activity found in association with intracisternal A-type particles.

A DNA polymerase activity that promotes the synthesis of poly(dT) has been found in association with intracisternal A-type particles isolated from several mouse tumors. The poly(dT) synthesis activity requires a DNA or RNA primer, is optimal at high salt concentration, prefers magnesium over manganese, and is stimulated by poly(rA). No significant incorporation of dAMP, dGMP, or dCMP was detected in the presence of several RNA and DNA template-primers. The enzyme activity differs in several of its properties from the poly(rA)-directed DNA polymerase activity associated with Rauscher murine leukemia virus.

Adenine Nucleotides↗
PubMed1970

Cytoplasmic particles and aminoacyl transferase I activity.

It has been possible to show by electron microscopy of samples selected from sucrose gradients that particles of specific size and shape are present in supernatant fluids derived from nucleated animal and plant cells, but not in extracts from Escherichia coli. Aminoacyl transferase I activity in these same gradients sediments in two peaks representing material of approximately 5-7S and 18-20S. A rectangular particle, 100 x 145 A in size, sediments at 19S and coincides with the second peak of transferase I activity. The possibility that the rectangular particle may be a "carrier" particle associated with transferase I is discussed.

Animals↗