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Biomedical subjects

T Kamikubo

Publications and source records attributed to T Kamikubo.

27 records · Page 2Linked to original sources
PubMed1977

Formation of cobalt-free corrinoids in Rhodopseudomonas spheroides.

Co-free corrinoids (CFCs) were found in the cells of Rhodopseudomonas spheroides grown without cobalt salt. A predominant fraction of three CFCs on paper-electrophoregram was further purified, and investigated physico-chemically as well as microbiologically in comparison with that isolated by Toohey from Chromatium. The electrophoretic as well as spectrophotometric patterns of CFC from Rh. spheroides were partly different from those of Chromatium CFC. The former CFC was a competitive inhibitor of cyanocobalamin in Ochromonas malhamensis. The findings obtained indicate that the CFC from Rh. spheroides resembles that from Chromatium in chemical structure with some difference, and that the compound has an anti-vitamin B12 activity in O. malhamensis.

Antimetabolites↗
PubMed1976

Template activity of synthetic deoxyribonucleotide polymers in the eukaryotic DNA-dependent RNA polymerase reaction.

Template specificities of the eukaryotic DNA-dependent RNA polymerases A and B from rat liver, pea, and cauliflower have been investigated using synthetic polydeoxyribonucleotides. Polymerases A and B from the three species exhibit different specificities for single-stranded homopolymers: polymerase A preferentially reads poly(dT) and poly (dC). and polymerase B poly (dC). This preferential reading appears to be a property of eukaryotic DNA-dependent RNA polymerases. Polymerases A and B transcribe synthetic polyribonucleotides also, but at a reduced rate. The polyribonucleotides which can be read by DNA-dependent RNA polymerases have a base sequence similar to that of the polydeoxyribonucleotides, which are effeciently transcribed, suggesting that the base sequence of the template rather than its conformation is crucial in the template specificity for synthetic polymers. Competition experiments with polydeoxyribonucleotides indicate that the enzymes have different binding specificities, which are not the same as their template specificities.

Animals↗