Showing papers in "Archives of Biochemistry and Biophysics in 1971"

TL;DR: It is concluded that the DPNH enhancement of the overall hydroxylation reaction is dependent on the presence of an apparent rate-limiting step in the TPNH-dependent reaction as demonstrated by modifying this step with cations.

TL;DR: The data indicate the existence of at least two forms of benzo[ a ]pyrene hydroxylating enzyme systems in rat tissues which can be differentially induced in vivo by administration of phenobarbital or methylcholanthrene.

TL;DR: Techniques, developed during the course of a series of investigations on somatic cell hybrids in this laboratory, are described for the electrophoretic characterization of glycose-6-phosphate dehydrogenase, nicotinamide adenine dinucleotide phosphate-dependant isocitrate dehydrogen enzyme, and phosphoglycerate kinase 2 in the man-mouse and man-Chinese hamster somatic Cellogel systems.

TL;DR: The source of reducing equivalents for gluconeogenesis is examined and it is concluded that transfer of carbon occurs both as malate and aspartate, and that the requirement for reducing equivalents is met in part by the transfer of malate to the cytosol and by NADH generated by the fumarate cycle geared to urea production.

TL;DR: In this report, a procedure is described for the large-scale purification from the bacterium Pseudomonas putida of two components of the camphor methylene hydroxylase system, cytochrome P-450 and putidaredoxin.

TL;DR: It is concluded that N 5 -methyltetrahydrofolate-homocysteine methyltransferase activity contributes significantly to the regulation of methionine metabolism in mammals.

TL;DR: The results suggest that the temperature-induced change in activation energy of the membrane-bound enzymes is associated with a phase change in the lipid component of the membranes which induces a configurationalchange in the enzyme proteins.

TL;DR: Pre-phenoloxidase has been purified approximately 360-fold from larval hemolymph of the silkworm Bombyx mori and the preparation appears to be homogeneous by criteria of disc electrophoresis and ultracentrifugation, although the protein tends to associate irreversibly.

TL;DR: Findings point to a possible role of the PDH interconversion for the regulation of pyruvate metabolism in diabetes and in other metabolic conditions where fatty acids are preferentially oxidized.

TL;DR: Actinomycin D given prior to 1,25-dihydroxycholecalciferol or 25-hydroxycholespecificum D blocks the bone mineral mobilization response in contrast to the previous finding that the intestinal transport response to 1-25- dihydroxchole CalCiferol is insensitive to this antibiotic.

TL;DR: The different oxygen-binding behavior of the isolated components can explain data obtained with the whole blood and in particular the contribution of the various proteins to the Root effect.

TL;DR: The metabolic stimulation of PMN leucocytes by phagocytosis is supported by changes in kinetic properties of NADPH oxidase, which induces a 3-fold increase of the intracellular NADP + NADPH ratio, without affecting the NAD+ NADH ratio.

TL;DR: It was concluded that cytochrome P-450 was responsible for most of the peroxidase activity of liver microsomes and a mechanism for the microsomal peroxIDase activity is proposed in which LAHPO oxidizes the P- 450 thiol ligand to form high spin P-420.

TL;DR: Treatment of blood group H substance at a concentration of 1 mg/ml with O.05 n NaOH and 1 m NaBH 4 at 50 ° results in the release of oligosaccharide side chains with a minimum of degradation.

TL;DR: Studies on the pattern of inhibition suggest a rigid electron-transport system linking a single molecule of TPNH-cytochrome c reductase to a number of molecules of cytochrome P-450 contained within a multicomponent complex and that reducing equivalents can be transferred only within a single enzyme complex with no demonstrable electron transfer interactions between the components of different complexes.

TL;DR: The primary structure of human pituitary growth hormone has been reinvestigated and it was found that a segment of the sequence containing the single tryptophan residue was misplaced and that two amino acid residues must be added to the original 188 amino acids in the HGH molecule.

TL;DR: The activation energy for this reaction is 20 Kcal per mole as discussed by the authors, which is the activation energy of the Franck-Condon addition of an electron to ferricytochrome c in room temperature.

TL;DR: It has been shown that pH is an important factor in the separation of 2,3-diphosphoglycerate from hemoglobin and the abnormally high mobility in neutral solution can be explained by electrostatic repulsion within the molecule, giving it an extended conformation.

TL;DR: In this article, the authors identified the strain (B 111-1) showing the highest lytic activity as Arthrobacter luteus, and the optimum pH for lysis of viable yeast cells was 7.0-8.0.

TL;DR: Ellman's reagent, 5,5′-dithiobis[2-nitrobenzoic acid] (DTNB) is a standard reagent for the determination of reactive sulfhydryl groups by absorbance measurement at 412 nm and established methods for the fast and accurate determination of the number of sulfHydryl and disulfide groups in proteins.

TL;DR: It is concluded that hydrophobic rather than electrostatic interactions predominate in determination of the grana structure and are relevant to functional studies of the coupling of electron flow between the two photosystems and of energy conservation in the form of ion gradients and ATP.

TL;DR: The concepts of amplification, parameter sensitivity, and feedback effectiveness in biochemical systems are presented and explored using a method of mathematical analysis previously developed for biochemical systems, and the values of these properties can be predicted, using this theory, from knowledge of the component parts of the system.

TL;DR: It is shown that high hydrostatic pressure will dissociate protein multimers which are held together by noncovalent interactions, and this dissociation must be considered as the major determinant of the effect of pressure on enzymic systems which depend upon such protein-protein interactions for their activity.

TL;DR: An extracellular amylase from Pseudomonas stutzeri was purified over 1000-fold by ammonium sulfate and acetone precipitations, which resulted in the exclusive production of maltotetraose and a high molecular-weight limit dextrin from amylopectin and glycogen.

TL;DR: Spectrophotomet and spectrophotometric titrations of the OA:BSA complex indicate that the interaction occurs in the pH region where the protein structure is undergoing a profound change.

TL;DR: The synchronization of metabolism between individual yeast cells, which is described here, may be important as an example of a phenomenon common to many different cell types.

TL;DR: The levels of docosahexaenoic acid in rod outer segment phospholipids are among the highest yet reported for membrane phospholIPids, amounting to 23% in phosphatidyl choline, 39% in phosphate-based ethanolamine, and 45% in phosphorus-based serine.

TL;DR: These studies suggest that the mitochondrial mechanism for cation uptake shows relatively little specificity as to cation, and Zn++ appears to have little effect on the permeability of the mitochondrion to cations in the absence of an energy source.

TL;DR: Thallium (I) has been found to serve as the required monovalent cation in the activation of rabbit muscle pyruvate kinase and an inhibition of the reaction occurs which is shown to be most likely due to the formation of the T1 + -ADP complex.