The arrangement of the protein component on the DNA of the chromatin complex was studied by comparing the rate of release of oligonucleotides and of protein after addition of deoxyribonuclease I and deoxyribonuclease II to rat thymus chromatin. Also the action of deoxyribonuclease I on normal chromatin and on chromatin depleted of non-histone protein was compared, to elucidate the role of the l...

The Streptonase B test was compared with the Center for Disease Control streptococcal anti-deoxyribonuclease B test. A total of 96% of anti-deoxyribonuclease B titers obtained with the Streptonase B test were within +/- 1 dilution step of those obtained with the Center for Disease Control anti-deoxyribonuclease B test.

In the single radial enzyme-diffusion (SRED) method for assay of deoxyribonuclease I, a precisely measured volume of the enzyme solution is dispensed into a circular well in an agarose gel layer in which DNA and ethidium bromide are uniformly distributed. A circular dark zone is formed as the enzyme diffuses from the well radially into the gel and digests substrate DNA. The diameter of the dark...

Four groups of deoxyribonuclease activities from human lymphocytes have been characterized by deoxyribonuclease assay in DNA-containing polyacrylamide gels following their separation by disc-electrophoresis. All activities hydrolyse DNA endonucleolytically. One neutral deoxyribonuclease found in the cytoplasmic fraction prefers native or UV-irradiated DNA over denatured DNA as substrate and is ...

The relationship of catalase, cystinase, and deoxyribonuclease activity to toxinogeny in Corynebacterium diphtheriae was examined. Mutants deficient in each activity were isolated after mutagenization of strain C4 with nitrosoguanidine. All mutants were converted to toxinogeny after lysogenization with beta-converting phage, thus establishing that there is no absolute link between toxin product...

A three-hour test has been developed to determine deoxyribonuclease activity of Enterobacteriaceae and staphylococci. The test is inexpensive and easy to perform. The rapid deoxyribonuclease test and the conventional method showed complete agreement with the strains tested.

Plaquing of a newly isolated phage of Bacillus subtilis, phage 41c, is only 2% efficient in agar containing 200 mug of deoxyribonuclease per ml. Timed deoxyribonuclease addition experiments showed that phage development is blocked in 90% of the cells if deoxyribonuclease is present during adsorption (zero-time samples), whereas 10 min after adsorption the enzyme has little effect (10-min sample...

Extracts of purified mitochondria from adult rabbit liver and kidney have been prepared by lysis with Triton X-100. Such extracts contain deoxyribonuclease activity demonstrable at alkaline pH. Studies utilizing the effects of substrate variation, differing ionic strength, nucleoside di- and triphosphates, and SH-group inhibitors reveal the existence of at least five distinguishable deoxyribonu...

Deoxyribonuclease II (Deoxyribonucleate 3’-nucleotidohydrolase, EC 3.1.4.6) was purified 1250-fold from bovine spleen. The specific activity of the final preparation was 408. It was free of phosphatase and alkaline ribonuclease, and almost free of nonspecific phosphodiesterase, acid ribonuclease, and adenosine triphosphatase. Chromatography on carboxymethyl cellulose prior to heating caused the...