Showing papers in "Journal of Biological Chemistry in 1968"

TL;DR: The spectrophotofluorometric determination of hydroxylated benzo[a]pyrene products is sufficiently sensitive to detect 10-12 mole per ml and has great utility in measuring the hydroxymatic activity of cells grown in culture.

TL;DR: A protein kinase that catalyzes an adenosine 3',5'-monophosphate (cyclic AMP)-dependent phosphorylation of casein and protamine has been purified from rabbit skeletal muscle.

TL;DR: Micromethods have been developed and 35S-labeled chondroitin sulfates A, B, and C in a given mixture have been precisely and rapidly determined by measuring radioactivity alone.

TL;DR: An enzyme, "chondroitinase-ABC," has been purified to apparent homogeneity from extracts of Proteus vulgaris, NCTC 4636, which was adapted on a medium containing chondroit in sulfate C, and its properties have been compared with those of chondro-4-sulfatase- ABC from P. vulgaris.

TL;DR: The data are consistent with the conclusion that xanthine oxidase generates an unstable reduced form of oxygen, presumably the superoxide anion, and that this radical is the agent which directly reduces cytochrome c and initiates the sulfite-oxygen chain reaction.

TL;DR: It has been shown that in the presence of a NADPH2-generating system prostatic nuclei convert testosterone to dihydrotestosterone, whereas prostatic cytoplasm reduces dihydotestosterone to androstandiol.

TL;DR: Two immunochemically distinct mucins have been isolated from pig submaxillary glands according to the ability of aqueous extracts of these glands to inhibit hemagglutination of human type A erythrocytes and are designated A+-PSM and A--PSM.

TL;DR: Dimethyl sulfoxide can replace the latter, volume for volume, in a ninhydrin reagent mixture that gives equal performance and has improved stability, and is recommended to replace methyl Cellosolve-containing reagents in the quantitative determination of amino acids by automatic analyzers and by the manual ninHydrin method.

TL;DR: The purified β2-microglobulin is devoid of carbohydrate and appeared homogeneous in Ouchterlony immunodiffusion, immunoelectrophoresis, starch gel electrophoresIS, and ultracentrifugation.

TL;DR: Phenylglyoxal (14C-labeled, if desired) may be useful for modification of accessible arginine residues in proteins and may be potentially useful for reversible coverage of arginin residues so that tryptic hydrolysis can take place at lysine residues only.

TL;DR: An enzyme system which catalyzes the ω-hydroxylation of fatty acids in the presence of reduced triphosphopyridine nucleotide and molecular oxygen has been obtained in a soluble form from rabbit liver microsomes.

TL;DR: In combination, epinephrine and caffeine acted synergistically, producing large increases in cyclic AMP, indicating that, as in other systems, the catecholamines act to stimulate adenyl cyclase and the methyl xanthines act to inhibit the cyclic nucleotide phosphodiesterase.

TL;DR: In the presence of diphtheria toxin, the adenosine diphosphate ribose portion of nicotinamide adenine dinucleotide was transferred to aminoacyl transferase II obtained from rat liver, which resulted in a concurrent inactivation of this particular enzyme.

TL;DR: Injection into rabbits of radioactive ceruloplasmin from which sialic acid had been removed enzymatically resulted in a rapid disappearance of the asialoceruloplAsmin from the serum and its appearance in parenchymal cells, but not in Kupffer cells, of the liver.

TL;DR: The purification procedure involved the use of ammonium sulfate precipitation, gel filtration on Sephadex G-100, and preparative disc electrophoresis, and an equation linearly relating binding protein concentration to binding activity indicated that the product was homogeneous with respect to size.

TL;DR: A nuclease with specificity for double-stranded RNA (RNase III) has been found in extracts of Escherichia coli and appears to be endonucleolytic, with an absolute requirement for divalent cations and for monovalent cations.

TL;DR: A specific and sensitive assay for disulfide groups has been developed, based on reduction with dithioerythritol or dithiothreitol and determination of the resulting monothiols with 5,5'-dithiobis(2-nitrobenzoic acid) in the presence of arsenite.

TL;DR: The coupling of the hydroxylase to the reduced diphosphopyridine nucleotide dehydrogenase (reductase), and the putidaredoxin is demonstrated, and substrate is shown to be required for the over-all reaction.

TL;DR: It is indicated that methotrexate transport in the L1210 cell is carrier-mediated and uphill, and the implication of these findings with respect to the development of more effective folic acid antagonists is considered.

TL;DR: Intact heme groups undergo exchange between molecules of human hemoglobin under physiological conditions, although at equilibrium the affinity of human albumin for ferriheme is only about one-fifteenth that of globin.

TL;DR: It was shown that dihydrotestosterone was bound to an acidic nuclear protein and was stable to freezing for as long as 8 days, stable to short term incubation at 20° but not at 37°, and partially stable to repeated gel filtration on Sephadex.

TL;DR: Kinetic studies indicate that the interactions between the polymerase-DNA structure and the deoxynucleoside triphosphates and Mg++ or Mn++ are complex, and there are only one or two sites of initiation on helical linear DNA molecules, and that reinitiation on a synthetic complex does not occur.

TL;DR: The similarities in the behavior of the BPA and BMA non-mercaptalbumin monomer fractions are somewhat surprising since the presence of these non-Mercapt albumin fractions in plasma albumin has been shown to be due to mixed disulfide formation between mercaptalbumin and plasma cysteine and glutathione.

TL;DR: Liver mitochondria derived from rats injected with leucine-3H and with phosphate-32P or with glycerol-14C were incubated with nonlabeled microsomes in the presence of supernatant or of sucrose-EDTA to measure exchange of phospholipid.

TL;DR: Polynucleotide ligase has been purified 1000-fold from extracts of Escherichia coli infected with bacteriophage T4 to eliminate the necessity for enzyme assays during the early fractionation steps and to permit the use of a simple assay, based on ATP-PPi exchange, during the later stages of purification.

TL;DR: Radioactive labeling of the 5'-termini of DNA with polynucleotide kinase has been used in conjunction with treatment by alkaline phosphatase from Escherichia coli to study single strand breaks (phosphodiester bond interruptions) produced in duplex DNA molecules by the action of pancreatic deoxyribonuclease.

TL;DR: Binding of glucocorticoids and related steroids to rat thymus cells in vitro has been measured by equilibrium and kinetic methods, adding to the evidence that the hormonally active form of cortisol is cortisol itself.

TL;DR: Prostaglandin E1 lowered cyclic AMP levels in isolated fat cells very rapidly, and was effective against adrenocorticotropic hormone, glucagon, and thyroid-stimulating hormone as well as the catecholamines.

TL;DR: Treatment of skeletal muscle microsomes with phospholipase C inhibits the adenosine triphosphatase activity and calcium transport, parallel with the selective hydrolysis of membrane lecithin, and is accompanied by tight binding ofospholipids to the microsomal membrane.