M1 RNA, the catalytic RNA subunit of RNase P from Escherichia coli, has been covalently linked at its 3' terminus to oligonucleotides (guide sequences) that guide the enzyme to target RNAs through hybridization with the target sequences. These constructs (M1GS RNAs) have been used to determine some minimal features of model substrates. As few as 3 bp on the 3' side of the site of cleavage in a ...

Administration of 9a-fluoroprednisolone to mice bearing the corticoid-sensitive strain of Lymphosarcoma PI 798 resulted in a prompt regression of tumor size. This regression was accompanied by a selective decrease in tumor RNA. Tumor DNA con centration remained at control levels. These changes were preceded by an increased tumor ribonuclease activity in homogenates of tumor after the in vivoadm...

Translating proteases as inactive precursors, or zymogens, protects cells from the potentially lethal action of unregulated proteolytic activity. Here, we impose this strategy on bovine pancreatic ribonuclease (RNase A) by creating a zymogen in which quiescent ribonucleolytic activity is activated by the NS3 protease of the hepatitis C virus. Connecting the N-terminus and C-terminus of RNase A ...

A thermostable enzyme capable of digesting d-ribose (yeast) nucleic acid was first described by W. Jones in 1920 (1). A partial purification of this enzyme with acetone was carried out by Dubos and Thompson who called the enzyme ribonuclease (2). Kunitz described the preparation and properties of a crystalline protein he isolated from beef pancreas which appeared to be the same as the ribonucle...

Ribonuclease B is a constituent of the zymogen granules of bovine pancreatic acinar cells and is secreted in the pancreatic juice of cattle (2). Its isolation from bovine pancreatic juice has been described (3). The enzyme is a glycoprotein that possesses an amino acid composition indistinguishable from that of ribonuclease A and contains carbohydrate to the extent of 6 residues of mannose and ...

Ribonuclease (RNase) A can be endowed with cytotoxic activity by enabling it to evade the cytosolic ribonuclease inhibitor protein (RI). Enhancing its conformational stability can increase further its cytotoxicity. Herein, the A4C/K41R/G88R/V118C variant of RNase A was created to integrate four individual changes that greatly decrease RI affinity (K41R/G88R) and increase conformational stabilit...

The Ribonuclease A Superfamily is composed of a group of structurally similar peptides that are secreted by immune cells and epithelial tissues. Several members of the Ribonuclease A Superfamily demonstrate antimicrobial activity, and it has been suggested that some of these ribonucleases play an essential role in host defense. Ribonuclease 7 (RNase 7) is an epithelial-derived secreted peptide ...

Thompson, T. L. (University of Nebraska, Lincoln), and J. M. Shively. Lethal action of ribonuclease for thermophilic bacilli. J. Bacteriol 91:673-676. 1966.-Exposure of a thermophilic bacillus, NU 47, to 0.2 mug/ml of pancreatic ribonuclease resulted in a drastic reduction of viable cells. The observed lethality is thought to be associated specifically with the ribonuclease, since heat treatmen...

A comparison between the levels of ribonuclease inhibitor in normal rat liver and Novikoff hepatoma 105,000 X g supernatant fractions is reported. Novikoff hepatoma con tained 61% less inhibitor per g of tissue or 39% less per mg protein than did normal rat liver. A rapid and simple method that had been developed for the purification of rat liver ribonuclease inhibitor was applied to Novikoff h...