DNA restriction fragments and PCR products were separated by means of ion-pair reversed-phase high-performance liquid chromatography on alkylated non-porous poly(styrene-divinylbenzene) particles with a mean diameter of 2.1 microns. Optimum resolution was obtained by using an acetonitrile gradient in 100 mM of triethylammonium acetate and a column temperature of 50 degrees C. This allowed the s...

The genes for tranfer ribonucleic acid (tDNA) and 5S ribonucleic acid (5SDNA) were isolated from the total deoxyribonucleic acid (DNA) of Escherichia coli. The relatedness of tDNA and 5S from E. coli and other species of Enterobacteriaceae was determined by reassociation of the isolated genes labeled with 32PO4 to unlabeled, unfractionated DNA. Double-stranded DNA was separated from unreacted D...

A sequence-specific nicking endonuclease from Streptomyces designated as DC13 was purified to near homogeneity. Starting with 30 grams of wet cells, the enzyme was purified by ammonium sulfate fractionation, DEAE cellulose, and phenyl-Sepharose chromatography. The purified protein had a specific activity 1000 units/mg and migrated on SDS-PAGE gel with an estimated molecular weight of 71 kDa. De...

A purification process for the monoclonal anti-CD4 antibody MAX.16H5 was developed on an analytical scale using (NH4)2SO4 precipitation, anion-exchange chromatography on MonoQ or Q-Sepharose, hydrophobic interaction chromatography on phenyl-Sepharose and gel filtration chromatography on Superdex 200. The purification schedule was scaled up and gram amounts of MAX.16H5 were produced on correspon...

Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase alpha on phosphocellulose and from each other on heparin-Sepharose. Form HS1 enzyme was 30-40% pure and for...

A cationic protein that stimulates DNA synthesis in human cultured cells was isolated from human platelets by ion exchange chromatography, hydrophobic chromatography, gel chromatography, and gel electrophoresis in sodium dodecyl sulfate. The electrophoretic behavior of biologically active or radioiodinated and reduced growth factor indicated that the native protein (approximately 30,000 daltons...

Dibenzo[a,l]pyrene (DB[a,l]P), an environmental hydrocarbon and very potent carcinogen in rodent bioassays, could be activated to DNA-binding intermediates in cells through formation of three different regioisomeric bay- or fjord-region diol-epoxides or other more highly oxidized metabolites. The mechanism of metabolic activation of DB[a,l]P in the human mammary carcinoma cell line MCF-7 was el...

the histone-like protein hu is the most-abundant dna-binding protein in bacteria. the hu protein non-specifically binds and bends dna as a hetero- or homodimer, and can participate in dna supercoiling and dna condensation. it also takes part in dna functions such as replication, recombination, and repair. hu does not recognize any specific sequences but shows a certain degree of specificity to ...