1. RNA was isolated from crude nuclear preparations and from ribosomes derived from rat brain and liver. Nuclear RNA was obtained by lysis of the nuclei with sodium dodecyl sulphate, followed by denaturation and removal of DNA and protein with hot phenol. 2. Base composition analyses indicated that the cerebral nuclear RNA preparation contained a h...
Specific aminoacyl-tRNA's from different mammalian organs and species have been compared by methylated albumin column chromatography. The elution profile of such chromatographs were usually similar, both between tRNA's from different organs in the same animal, and across widely divergent mammalian species. Species differences were found in the elut...
1. Cerebral RNA of adult and newborn rats was labelled in vivo by intracervical injection of [5-(3)H]uridine or [(32)P]phosphate. Hepatic RNA of similar animals was labelled by intraperitoneal administration of [6-(14)C]orotic acid. Nuclear and cytoplasmic fractions were isolated and purified by procedures involving extraction with phenol and repea...
1. Chromatin was prepared from purified nuclei isolated from liver and cerebral regions of the rat. 2. The capacity of these preparations to promote RNA synthesis in the presence of bacterial RNA polymerase was determined. 3. The rate of RNA synthesis on chromatin was normally 12-21% of the rate observed with native DNA, but was markedly stimulated...
Cell-free extracts of the protozoan Tetrahymena pyriformis have been found to catalyze the following reactions: Phosphatidylethanolamine + L-Serine Phosphatidylserine + Ethanolamine. Phosphatidylserine --> Phosphatidylethanolamine + CO(2) divided by Net: L-Serine --> Ethanolamine + CO(2). The biosynthesis of phosphatidylserine in this organism res...
1. Acetylation of histones by an enzyme system derived from rat brain and liver (histone acetylase) was studied by using [1-(14)C]acetyl-CoA as the acetyl group donor. 2. The activity of this enzyme was largely confined to the nucleus. 3. Histone-acetylating activity of cerebral nuclei purified by centrifugation through 1.9m-sucrose was not altered...
Experimental data are presented on the intracellular localization in rat liver of three enzymes which are involved in the biosynthesis of phosphatidylethanolamine and diphosphatidylglycerol. These enzymes are phosphatidylserine decarboxylase, CDP-diglyceride-l-alpha-glycerophosphate phosphatidyl transferase, and phosphatidylethanolamine-l-serine ph...
The polypeptides synthesized in an E. coli cell-free system under the direction of the small RNA of the satellite tobacco necrosis virus were compared with the authentic coat protein of this virus. Many of the tryptic peptides obtained from the two types of proteins moved identically upon high-resolution cation exchange column chromatography, but d...
A kinetic analysis is presented for the dependence of one form of phospholipase A(2) from cobra (Naja naja) venom on the presence of the nonionic detergent Triton X-100 for its activity towards egg phosphatidylcholine and synthetic dipalmitoyl glycerophosphorylcholine as substrates. An automatic recording pH-stat apparatus was employed in order to ...
A new rapid assay for phosphatidylserine decarboxylase, which is sensitive in the nanomolar range, is described. Synthesis of radiolabeled phosphatidylserine for use as a substrate is not required, since the assay, unlike previous ones, is based on the detection of CO(2) liberated from unlabeled phosphatidylserine. The assay employs a gas chromatog...
