Specific inhibitors of each of the three RNA polymerases of Blastocladiella emersonii have been found. Cycloheximide specifically inhibited the in vitro activity of the DEAE-fraction I enzyme, alpha-amanitin specifically inhibited the DEAE-fraction II enzyme, and rifampicin specifically inhibited the fraction III enzyme. DNA stimulation and dependency on the four riboside triphosphates were sho...

Solubilized protein fractions have been obtained from plasma membranes of Ehrlich ascites cells either by extraction with 0.5% Triton X-100 or by extraction with 2% cholate. Partial purification of the solubilized protein fraction has been obtained by utilizing a combination of ammonium sulfate precipitation and column chromatography. Leucine-binding activity has been detected in the Triton X-1...

The fraction (venom B) of spine venom from the crown-of-thorns starfish (Acanthaster planci) caused contractions of the uterus of rats and enhanced vascular permeability in rabbits. The venom B-induced contraction of the smooth muscle was depressed by inhibitors of prostaglandin synthesis such as indomethacin or aspirin, but not by the anticholinergic agent, atropine. The fraction with the uter...

A glucosyl and a glucosyl-glucan transferase activity from spinach (Spinacia oleracea L. var. Matador) leaves have been partially purified and characterized. The latter activity (fraction 1 after diethylaminoethylcellulose chromatography) is responsible for the transfer of glucosyl as well as of maltosyl, maltotriosyl, and higher homologous residues to glucose giving rise to maltose and the cor...

Diisopropyl fluorophosphate (DFP) effectively inhibited proteolytic activity in preparations of partially purified Streptomyces albus enzyme used to lyse cell walls of Group A streptococci. Lysis of non-trypsinized Group A cell walls with DFP-treated S. albus enzyme released a soluble protein fraction containing antigenic type-specific M protein, a carbohydrate fraction consisting of Group A an...

We have partially purified replicating simian virus 40 (SV40) chromosomes in a form which allows continued DNA synthesis in vitro. We first prepare a soluble DNA-synthesizing system from SV40-infected monkey cells and then sediment the components through a neutral sucrose gradient of extremely low ionic strength. Replicating SV40 chromosomes isolated from such gradients are capable of continuin...

Attempts to prevent the urea conversion of a 200-230,000 molecular weight DNA polymerase alpha to a 150-170,000 molecular weight form by the inclusion of protease inhibitors have not been successful. No other method has been found capable of dissociating a 50-70,000 fragment or subunit from the DNA polymerase subunit. Addition of this 50-70,000 subunit to the polymerase subunit does not aid the...

Adenosine kinase has been partially purified from homogenates of rabbit liver and Ehrlich ascites tumor cells. The kinase preparation obtained was free of adenosine deamlnase and almost free of adenosine triphosphatase activity. In addition to adenosine, 34 analogues or derivatives of adenosine have been investigated with the enzyme. Of these compounds, 16 were substrates, and the Michaelis con...

A kinase that catalyzes the phosphorylation of deoxycytidine has been purified 150-fold from L1210 murine leukemia cells. The reaction requires a divalent cation (preferably Mg++ or Mn++) and a nucleoside triphosphate. Optimal activity was obtained with ATP. Phosphorylation of deoxycytidine was competitively inhibited by both proximal (dCMP) and distal (dCDP and dCTP) end products and by cytosi...

In this study we developed a new method for the partial purification of Pasteurella haemolytica leukotoxin by size-exclusion high-performance liquid chromatography. The partially purified leukotoxin had a molecular weight of 104,000, as estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reacted on an immunoblot with an antileukotoxin monoclonal antibody. As expect...