Showing papers in "Biochemical and Biophysical Research Communications in 1975"

TL;DR: Tunicamycin inhibited the production of the [3H]G1cNAc-lipid but did not affect the synthesis of the 14C-mannolipid, which accounts for the effect of the antibiotic upon glycoprotein formation in vivo.

TL;DR: A function of ascorbic acid as a defense against O2− is presented and a kinetic analysis of the inhibition of this reaction by superoxide dismutase shows that the second-order rate constant for the reaction between ascorBic acid and O2 − at pH 7.4 was estimated to be 2.7 × 105 M−1 sec−1.

TL;DR: Heterogeneous populations of liposomes were cleared from the rat bloodstream in a complex manner, with a rapid phase and a slow phase of removal.

TL;DR: It is found that Hb A1c contains neutral sugars which are only partially hydrolyzed from the N-termini of β chains, and it is proposed that in the red cell, glucose binds to the α-amino position of hemoglobin β-chains (valine) in an aldimine (Schiff base) linkage.

TL;DR: A new parameter is proposed, the average affinity of the receptor sites, K, calculated as ( B F/(R o −B) , which has been successfully applied to the negative cooperativity of insulin receptors.

TL;DR: Findings indicate that brain adenylate cyclase required an activator for activity and that this activator is functionally identical to the protein activator of phosphodiesterase (J.B.C. 249: 4943–4954, 1974).

TL;DR: The ability of acetylation of 60% of lysine residues of horse heart ferricytochrome c to be reduced by 0 2 − radicals is maintained, making this derivative useful for the detection of 0 1 − radicals in biological systems containing cy tochrome c reductases or oxidases.

TL;DR: This work has shown that even though the nitro compounds are unchanged, both nitrofurantoin and p -nitrobenzoate profoundly increase the NADPH-supported oxygen uptake, suggesting that superoxide anion free radical is being formed by the rapid air oxidation of theNitroaromatic anion radical.

TL;DR: The interconversion of the active, nonphosphorylation form of pyruvate dehydrogenase and its inactive, phosphorylated form is modulated by acetyl-CoA/CoA and NADH/NAD molar ratios.

TL;DR: Both the temporal relation of intracellular and external cyclic-AMP spikes and the quantitative aspects indicate that oscillatory activation of adenylate cyclase is an important feature of the signal generating system that controls development of D. discoideum.

TL;DR: An overall homeostatic mechanism is proposed where metallothionein synthesis is controlled at the transcriptional level by body zinc status and functions in uptake and storage of zinc in hepatocytes and in the intestinal mucosal cells.

TL;DR: It is anticipated that liposomes designed to home may become important tools in the control of cell behaviour as well as mediating selective cellular uptake of the associated liposome and the entrapped drug.

TL;DR: The administration of ethionine results in a rapid and marked increase in cystathionine synthase in rat liver and the specific activity doubles within 20 minutes following a dose of 400 mg/kg.

TL;DR: The results suggest that in N2-fixing cultures of A. cylindrica the primary NH3 assimilating pathway involves GS, and probably glutamate synthase (GOGAT), and that the repressor of nitrogenase synthesis and heterocyst production is not NH4+ but is GS, GOGAT, or a product of their reactions.

TL;DR: The presence of this inhibitor of collagenase may account for previous inability to detect collagenase in human skin fibroblast cultures and it is also possible that some of the inactive enzyme exists in the medium in the form of a proenzyme.

TL;DR: Findings which indicate that mammalian enzymes can activate metronidazole to a genetically active intermediate may have a direct relevance to the carcinogenicity of this agent.

TL;DR: Study of interactions of 125 I-insulin with non-tissue materials are presented as examples of non- receptor (“nonspecific”) interactions which share, at least superficially, the criteria commonly attributed to “specific” hormone-receptor interactions.

TL;DR: Compounds 10 and 5 are synthesized by condensation of benzyl 2-acetamido-4,6-O-benzylidene-3-O-(D-1-carboxyethyl)-2-deoxy-β-D-glucopyranoside with the L-alanine derivative 2 and the dipeptide 7, followed by debenzylidenation and hydrogenolysis.

TL;DR: NADPH-cytochrome P-450 reductase with capacity to support cytochromeP-450-dependent drug metabolism and to reduce artificial electron acceptors has been purified to apparent homogeneity by solubilization with Renex 690 and chromatography on DEAE-Sephadex, Agarose and QAE-separatex.

TL;DR: Both cytochromes are catalytically active when reconstituted with lipid and NADPH-cytochrome c reductase and exhibit differential substrate specificities for benzphetamine and benzo[a]pyrene.

TL;DR: The presence of (−) alprenolol increases the rate of [ 3 H] (−)alprenlol dissociation, indicating that negatively cooperative interactions among the β-adrenergic receptor binding sites do occur.

TL;DR: The results suggest that the enhanced of the rat uterus to Oxytocin following estrogen treatment is the result of an increase in the affinity and number of oxytocin receptors in the uterus.

TL;DR: An efficient radioimmunoassay for quantifying the physiological level of Arthropod molting hormone has been realized, using a 125I — labelled analogue and a dialysis procedure to determination of ecdysone level in Drosophila melanogaster during the last larval instar and at the beginning of metamorphosis.

TL;DR: In vitro DNA chain breakage by bleomycin was enhanced by the addition of xanthine oxidase system and it is concluded that superoxide radical is one of the chemical mediators responsible for the enhancement of the DNAChain breakage action ofBleomycin.

TL;DR: The amino acid composition determined in the present study indicates that the content of cysteine is identical in the two forms of the enzyme thus permitting the proposal of a structure for β-thrombin which differs from that currently in the literature.

TL;DR: The absorption spectra of the adducts were identical with that obtained by reaction of chloroethylene oxide with 4-(4-nitrobenzyl) pyridine, and a common product of these reactions was tentatively characterized as 3-β-ribofuranosyl-imidazo-[2,1- i ]purine.

TL;DR: When incubated with a 9,000 x g rat-liver supernatant, benzo(a)pyrene 7,8-diol and benz( a)anthracene 8,9-dol were more active than the parent hydrocarbons in inducing his+ revertant colonies of S. typhimurium TA 100.

TL;DR: Methyl viologen enhanced the production of the 02 adduct thus providing support for the hypothesis that methyl viOLOGen accepts electrons from the primary acceptor of photosystem I and subsequently reduces 02 to 0, the new technique of spin trapping has been applied to a biological system for the first time.

TL;DR: Exposure of S. typhimurium strains TA 1530, TA 1535 and G-46 to vinyl chloride increased the number of his+ rev./plate 16, 12 or 5 times over the spontaneous mutation rate.

TL;DR: It was suggested that the ferryl ion (compound I) of cytochrome P-450 is the common “activated oxygen” species in these hydroxylations.