FACTORS AFFECTING THE RATE OF FLASHING AND LOSS OF LUMINESCENCE IN AN ASIAN LAND SNAIL, DYAKIA-STRIATA

Volume: 29Start Page: 394End Page: 39

A Mammalian Nicking Endonuclease

Purification and properties are described for an endonuclease isolated from calf thymus which attacks double- stranded, unmodified DNA, primarily by making singlestrand breaks. No detectable acid-soluble products arise from the reaction. Double-strand breaks may occasionally be produced by the introduction of single-strand breaks on opposite strands in close proximity. The enzyme does not attack denatured DNA and is not inhibited by tRNA. Although added divalent cations are not required for activity, the enzyme is inhibited by EDTA, which suggests an essential role for bound cations; reaction is inhibited by Ca. The endonuclease has a broad pH optimum and is inactivated by preincubation at temperatures of 45 °C and higher. The molecular weight as determined by gel chromatography is about 30 000. Analysis of the products of reaction on a defined substrate, bacteriophage T3 DNA, by sedimentation in alkaline sucrose density gradients indicates limit products with chain lengths of about 0.8 × 10 daltons. On electrophoresis in agarose gels these products were shown to be heterogeneous in size. The endonuclease appears to generate3'-hydroxyl and 5'-phosphate ends. The ability of the endonuclease to utilize bovine DNA as substrate argues against a restriction role for this enzyme

Pharmacokinetics of rituximab in a pediatric patient with therapy-resistant nephrotic syndrome

Transplantation and immunomodulatio