Rifampicin and streptolydigin, if used in conjunction with nystatin, depress the growth of Kluyveromyces lactis. The incorporation of labeled leucine into protein is inhibited by nystatin whereas the incorporation of labeled uracil into RNA is inhibited by rifampicin in nystatin-treated cells. In order to study the mechanism of inhibition of RNA synthesis we purified by DEAE-Sephadex column chr...

Calf-thymus chromatin was fractionated by ion-exchange chromatography on ECTHAM-cellulose and sucrose gradient sedimentation. [ECTHAM-cellulose is a cationic adsorbent prepared by coupling tris(hydroxymethyl)aminomethane to cellulose with epichlorohydrin.] The capacity of these fractionated chromatins to support RNA synthesis by DNA-dependent RNA polymerase of Escherichia coli was examined, usi...

The interaction of calf thymus histone H1 with homologous and heterologous DNA has been studied at different ionic strengths. It has been found that about 0.5 M NaCl histone H1, and its fragments N-H1 (residues 1-72) and C-H1 (residues 73-C terminal), precipitate selectively a small fraction of calf thymus DNA. This selective precipitation is preserved up to very high values (less than 2.0) of ...

The ratios of total histone to DNA for rat liver nuclei isolated by four methods as well as for calf liver nuclei isolated by one method were determined by obtaining the ratios of the total areas of the electrophoretic histone peaks for the liver nuclei to the corresponding total area given by a known amount of standard calf thymus histone. Ratios of total histone to DNA of approx. 2 for rat li...

The nature of stable DNA adducts derived from the very potent carcinogen dibenzo[a,l]pyrene (DB[a,l]P) in the presence of rat liver microsomes in vitro and in mouse skin in vivo has been studied using 32P-postlabeling and laser-based fluorescence techniques. Analysis of DB[a,l]PDNA adducts via 32P-postlabeling has been obtained by comparison of the adduct patterns to those obtained from reactio...

Organic solvents offer a new approach to formulate DNA into novel structures suitable for gene delivery. In this study, we examined the in situ behavior of DNA in N, N-dimethylformamide (DMF) at low concentration via laser light scattering (LLS), TEM, UV absorbance and Zeta potential analysis. Results revealed that, in DMF, a 21bp oligonucleotide remained intact, while calf thymus DNA and super...

The catalytic subunit of human DNA polymerase (pol) δ, p125, was expressed in recombinant baculovirus-infected insect cells, separated from a baculovirus-encoded DNA polymerase, and was purified to homogeneity by affinity trapping with a histidine-octapeptide at the C-terminus of p125 as the ligand. Purified p125 showed DNA polymerase activity resembling conventionally purified calf thymus pol ...

Hematoporphyrin derivative (HPD) plus photoradiation caused the inactivation of DNA polymerases from calf thymus and R3230AC rat mammary tumor. Photosensitization of purified DNA polymerase-alpha as well as two forms of DNA polymerase-delta (I and II) from calf thymus were evaluated. Although all polymerase enzyme forms were inactivated at 70 micrograms HPD/ml, DNA polymerase-delta II was the m...