In a study of the role of cathepsins in nuclear metabolism (1) these intracellular proteinases were found to hydrolyze thymus nucleoproteins and render dialyzable the desoxyribonucleic acid. Further characterization of this nuclease activity of the cathepsin preparations revealed pH optima in the acid range for both desoxyribonucleic acid (DNA) and ribonucleic acid (RNA). This was in contrast t...

Feulgen bands can be obtained at the sites of constitutive heterochromatin in the chromosomes of Anemone blanda, Fritillaria lanceolata and Scilla siberica, simply by means of a short or extended acid hydrolysis. Extended hydrolysis gives positive bands in A. blanda and F. lanceolata and negative bands in S. siberica. Short hydrolysis gives no bands in A. blanda and S. siberica but gives negati...

Hepatitis D virus (HDV) is a defective RNA with negative-strand genome encompassing less than 1700 nucleotides. The HDV encodes only for one protein, the hepatitis delta antigen (HDAg), which exists in two forms acting as nucleoproteins. depends on envelope proteins of B helper packaging its ribonucleoprotein complex (RNP). considered causative agent most severe form viral leading to liver fibr...

The effects of several concentrations of puromycin on the nucleoproteins of HeLa cells grown in monolayers were studied by cytochemical and biochemical techniques. The earliest change at all concentrations of puromycin was a decrease in a granular form of ribonucleoprotein (RNP) that is demonstrable in the normal HeLa cell by the toluidine blue-molybdate (TBM) stain. The other types of RNP reve...

Folic acid is a coenzyme for many important biochemical reactions including synthesis of purines, pyrimidines, and nucleoproteins. The recommended daily allowance of folic acid is 65 - 200 microg/day for infants and children. The recommended dose for deficiency states is 1000 microg/day; the effects of excess amounts of folic acid are unknown. The role of folic acid in preventing progression of...