Enzymes of cancer nuclei*1

Electron-Histochemical Investigation of the Enzyme Activity of Nuclear Ribonucleoproteins

“…These findings are in a good accordance with numerous biochemical (1,14,17,25,35,36) and histochemical (5,45) data.…”

“…dGTP more intensively that ATP), Siebert (35) believes that metabolic functions of these enzymes are associated with RNA rather than with DNA. This supposal is in a good accordance with our data and with data of Vorbrodt and Bernhard (45) on the localization of NTPase in the RNA-components of the nucleus.…”

An Improved Method for the Isolation of Rat Liver Nuclei by Density Centrifugation

“…U ndoubtedly the most serious remaining contamination is microsomal, representing the outer nuclear m e m b r a n e and pieces of the endoplasmic reticulum attached to it. This is indicated by the high glucose-6-phosphatase content (Table I), as found by other workers (11), although, since the enzyme cannot be brought into true solution, the validity of this assay must be considered dubious. About 65 per cent of the D N A in the filtered homogenate is recovered, FIGURE ~ Same nuclei as in Fig.…”

Enzymology of the Nucleus

“…The proof for substrate level phosphorylation of ADP during glycolysis depends on the following experimental observations : (1) Except for phosphoglyceric mutase, which has not been determined to date, all other enzymes of the glycolytic pathway have been found in isolated nuclei (7,144). (2) Metabolites of glycolysis are present in nuclei (Table IX and findings should be taken as definite proof of the existence of glycolysis in nuclei, since enzymes, substrates, and cofactors are present in nuclei.…”

“…Such nuclei, prepared in 2M sucrose, seem to retain, at least in the case of rat liver, most of the nuclear enzymes, although there is a loss of low molecular compounds such as acid-soluble nucleotides (28). However, in the field of non-aqueous isolation media, the applicability of this technique (6) for the study of enzymes has been clearly advanced (7,8,29). For a critical appraisal of aqueous and non-aqueous isolation methods for nuclei, the reader is referred to reviews (2-5,22).…”