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Biomedical subjects

B I Gerwin

Publications and source records attributed to B I Gerwin.

72 records · Page 4Linked to original sources
PubMed1975

Two active forms of RD-114 virus DNA polymerase in infected cells.

Two forms of DNA polymerase are present in RD-114-infected human, dog, and mink cells, but are not detectable in uninfected cells. The two enzymes are indistinguishable catalytically and immunologically, but differ with respect to molecular weight and elution position from (dT)12-18-cellulose and phosphocellulose. The large enzyme (equivalent 95,000 daltons) is found in the infected cells, but not the virions produced by these cells. The virions contain only the smaller enzyme (equivalent 70,000 daltons). The larger form may represent a mammalian viral equivalent to the beta subunit of avian RNA tumor virus DNA polymerase.

Cell Line↗
PubMed1973

DNA polymerase activities of human milk.

DNA polymerases have been partially purified from human milk. A DNA polymerase detected by phosphocellulose chromatography is similar to the enzymes of RNA tumor viruses in that a hybrid of polyriboadenylate and oligodeoxythymidylate is a better template than is DNA. However, this polymerase differed from that of the RNA tumor viruses in its chromatographic behavior. Three different methods of detecting "reverse transcriptase" activity failed to correlate with the donor's family history of cancer.

Breast Neoplasms↗
PubMed1973

Detection and isolation of a new DNA polymerase from human breast tumor cell line HBT-3 by (dT)12-18-cellulose chromatography.

Column chromatography on (dT)(12-18)-cellulose was used to detect and isolate a novel DNA polymerase activity from human breast tumor cell line HBT-3. The new enzyme is similar to those of mammalian RNA tumor viruses in its molecular size, preference for poly(A).(dT)(12-18) as compared to either poly(dA).(dT)(12-18) or poly(A).poly(dT), and ability to copy poly(C).(dG)(12-18). A similar DNA polymerase activity, defined by its binding to (dT)(12-18)-cellulose, is not detectable in several other cell lines of human tumors.

Adenine Nucleotides↗
PubMed1972

An oligonucleotide affinity column for RNA-dependent DNA polymerase from RNA tumor viruses.

Columns of (dT)(12-18)-cellulose provide a one-step enrichment procedure for RNA-dependent DNA polymerase. The enzyme of the virus from RD-114 cells, as well as that from Rauscher murine leukemia virus, have been purified in this way. The preference of viral as compared to cellular DNA polymerases for (dT)(12-18) as a primer is reflected in the fact that the DNA polymerases of uninfected cells do not bind to this column. Viral enzymes have been purified and identified from crude cellular extracts.

Animals↗
PubMed1969

Transcarboxylase. 8. Isolation and properties of a biotin-carboxyl carrier protein.

Methylmalonyl CoA-oxalacetate transcarboxylase (EC 2. 1. 3. 1) from Propionibacterium shermanii is a biotin enzyme of 670,000 molecular weight containing 6 moles of biotin per mole of enzyme. The active enzyme dissociates spontaneously at low ionic strength and alkaline pH to a mixture of inactive subunits. One type of subunit contains all the biotin of the original molecule. The biotin unit has an S(20,w) = 1.3S and a molecular weight of approximately 12,000. It contains 1 mole of biotin and 1 half-cystine per mole. Qualitative dansyl techniques indicate that alanine is the amino terminal residue of the biotin subunit.

Alanine↗