Rat liver nuclei were isolated and sonicated for extraction in order to study the capping of RNA. The guanosine 7-methyltransferase was purified from the extract by hydroxylapatite column chromatography with stepwise addition of phosphate buffer. It was assayed by using as methyl acceptor synthetic G(5')ppp(5')G and S-adenosylmethionine as donor. The enzyme appeared in a sharp peak at 160 mM. T...

The hydrolysis of glycerophospholipids in very low density lipoprotein by enzyme(s) released into circulation after the injection of heparin to rats was studied. [32P]Lysolecithin was formed rapidly from [32P]lecithin when very low density lipoprotein, labeled biosynthetically with 32P, was incubated with postheparin plasma. The [32P]lysolecithin was associated with the plasma protein fraction ...

Thrombin-induced aggregation and serotonin release were markedly enhanced in platelets from spontaneously hypertensive rats (SHR) when compared with those from normotensive Wistar-Kyoto rats (WKY). Since phosphoinositides are involved in calcium-mediated platelet responses, the metabolism of these lipids was investigated in SHR and WKY by using 32P-labeled quiescent platelets. In unstimulated c...

A 32P-labeled pyruvate kinase (L-type isozyme) was elicited in response to glucagon and has been isolated from suspensions of hepatocytes incubated with inorganic [32P]phosphate. The pyruvate kinase in crude extracts of hepatocytes was stabilized by ammonium sulfate fractionation, 30% glycerol, and 50 mM KF and the enzyme was isolated by immunoprecipitation with anti-liver pyruvate kinase immun...

The human erythrocyte actively phosphorylates and dephosphorylates phosphatidylinositol present in the membrane in an apparent "futile cycle." Recent reports have proposed that this phosphorylation/dephosphorylation cycle is a significant consumer of adenosine-5'-triphosphate (ATP) in the erythrocyte. This study details two independent techniques for quantitating the ATP consumed by this phosph...

Mitogenic stimulation of quiescent mouse 3T3 cells with epidermal growth factor leads to biphasic S6 kinase activation. The kinases present in both phases of the response have been purified from 32P-labeled cells and shown to contain a phosphoprotein of equivalent Mr 70,000. Chromatographic analysis of the purified S6 kinases on a Mono Q column reveals that (i) all 32P-labeled protein coelutes ...

Incorporation of 32p into RNA and DNA fractions of mammary and tumor tissue was studied in virgin C3H mice, which are susceptible to the development of breast cancer. Virgin C57BL mice, which are resistant to the development of breast cancer, were the controls. Virgin C3H and C57BL mice, 4 and a months old, and tumor-bearing C3H mice were used as the experimental groups. The incorporation of 32...

In 1954 a then 31 -yr-old male was found to have erythrocytosis. Over the ensuing decade he received 72 mCi 32P. In 1964 his daughters were found to have erythrocytosis. Further investigation led to the discovery of hemoglobin Yakima, a variant with high oxygen affinity. He received no further therapy and was well until 1975, when he developed the preleu. kemic syndrome. Within 12 mo he develop...