Histones are basic proteins associated with the DNA of eukaryotic cells, and appear to have a fundamental role in the organisation of the chromosomes of higher organisms [l-3] . Comparative primary sequence information is available for most of the major histones (for recent review see [3]). However the complete primary structure of histone H2B is known only for calf thymus [4] . Here we present...

The electrochemical behavior of o-nitrophenol was studied in detail with a glassy carbon electrode (GCE). The dependence of peak potential on pH indicated that equivalent electrons and protons were involved in the process of o-nitrophenol reduction. The interaction of o-nitrophenol with calf thymus DNA was investigated by adding DNA to the o-nitrophenol solution and by immobilizing DNA on GCE, ...

Two novel cobalt(III) pyridine complexes (1)[Co(en)2(py)2]3+ and (2)[Co(en)2(mepy)2]3+ (en=ethylenediamine, py=pyridine, and mepy=methylpyridine) have been synthesized and characterized. The interaction of these complexes with calf thymus DNA was investigated by absorption, emission spectroscopy, viscosity measurements, DNA melting, and DNA photocleavage. Results suggest that the two complexes ...

Arthur Kornberg isolated a new enzyme from E. coli, and called it “DNA polymerase” because of its ability to assemble nucleotides to manufacture strands of DNA. He could do this in vitro (in a test tube) by providing a pool of free nucleotides, a DNA primer (he used calf thymus DNA), a source of magnesium ions, and ATP. While the actual physiological role of this enzyme proved to be quite diffe...

1,2-Dioxetanes, efficient chemical sources of triplet excited carbonyl compounds, were observed to be genotoxic in isolated DNA, bacteria, and cultured mammalian cells. In superhelical DNA of bacteriophage PM2, various alkyl- and hydroxyalkyl-substituted dioxetanes (1) induced predominantly endonuclease-sensitive base modifications and only few single strand breaks. With a specific endonuclease...

The steps of the topoisomerization reaction by calf thymus DNA topoisomerase I on a DNA domain containing an intrinsically bent DNA sequence have been analyzed. High preferentiality of binding, cleavage and topoisomerization on the bent segment relative to the rest of the DNA domain was observed. These studies show the importance of the local DNA conformation in the reaction of eukaryotic DNA t...