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Showing papers in "Archives of Biochemistry and Biophysics in 1979"


Journal ArticleDOI
TL;DR: It is concluded that mitochondria have a set of protective mechanisms involving endogenous NADH, ADP, and energization which regulate the rate of the Ca2+-induced transition, and that the transition requires neither electron flow nor energy, but rather the mere accessibility of some internal site to Ca2+.

823 citations


Journal ArticleDOI
TL;DR: It is concluded that the trigger site (by “trigger site” the authors mean the site of binding of Ca2+ which, whenCa2+ is bound, will allow the transition in permeability to occur) is possibly also the site for high-affinity Ca2-induced uptake.

742 citations


Journal ArticleDOI
TL;DR: The effect of alloxan appeared paradoxical in that it increased cyanide-resistant respiration without significantly increasing the cell content of the manganese-superoxide dismutase and with only a small effect on the level of catalase.

575 citations


Journal ArticleDOI
TL;DR: Na2+-induced Ca2+ release was not accompanied by a configurational change; it is concluded that it is not mediated by the Ca2-induced transition.

521 citations


Journal ArticleDOI
TL;DR: Suspensions of cultured C 1300 neuroblastoma cells, sarcoma 180 ascites tumor cells, and Tetrahymena pyriformis cells provide direct evidence that in intact cells mitochondrial oxidative phosphorylation is oxygen dependent throughout the physiological range of oxygen tension.

362 citations


Journal ArticleDOI
TL;DR: Findings have important implications for cell function since any process which generates peroxides may activate the cyclooxygenase, which sets a peroxide tone that can regulate the rate of prostaglandin formation in cells.

355 citations


Journal ArticleDOI
TL;DR: Results support the view that ACC synthase is a pyridoxal enzyme, which catalyzes the conversion of S -adenosylmethionine to ACC and methylthioadenosine in tomato extract.

324 citations


Journal ArticleDOI
TL;DR: A model of hemispherical clathrate cages is proposed which if correct, would account for the differences in the data obtained by these two methods, and a weak correlation between the number of apolar residues and hydrodynamic hydration is found.

285 citations


Journal ArticleDOI
Efraim Racker1, B. Violand1, S. O'Neal1, M. Alfonzo1, J. Telford1 
TL;DR: This procedure is now the method of choice for the reconstitution of bacteriorhodopsin, and the proton pumps of mitochondria or chloroplasts, because of the observation that very short periods of sonication are required when certain solvents are present in low concentrations.

220 citations


Journal ArticleDOI
TL;DR: Results obtained provide evidence that the FMN and FAD are in highly different environments in the enzyme, as also indicated by the different redox potentials and oxygen reactivities of the flavins.

178 citations


Journal ArticleDOI
TL;DR: The model of Wilson and co-workers for the regulation of mitochondrial oxidative phosphorylation has been extended to include the dependence on oxygen tension and the derived rate expression correctly describes the observed dependence of cellular energy metabolism on oxygen pressure.

Journal ArticleDOI
TL;DR: The high specificity of these antibodies for a single form of Cytochrome P -450 was used to quantitate two forms of cytochromeP -450 in rat liver microsomes by radial immunodiffusion, which varied from 3 to 89% depending on the xenobiotic pretreatment of the rats.

Journal ArticleDOI
TL;DR: The specificity of two isolectins, A 4 and B 4, of Bandeiraea simplicifolia lectin I (BS-I) was studied by quantitative precipitin, precipitins inhibition, as well as by competitive binding assays using various blood group substances and tritium-labeled human B substance as mentioned in this paper.

Journal ArticleDOI
TL;DR: The results pointed to the importance of the positively charged guanido group, which appears to interact with and neutralize the negative charges on NAD(P)H and thereby allow for better enzyme-substrate interaction.

Journal ArticleDOI
TL;DR: The presence of cysteine, N -acetylcystine, or methionine in the medium protects hepatocytes from bromobenzene toxicity by providing intracellular Cysteine for GSH biosynthesis and it is suggested that an inhibitory effect on amino acid uptake may contribute to the cytotoxicity of bromOBenzene in hepatocytes.

Journal ArticleDOI
TL;DR: Relatively low amounts of this form of cytochrome P-450 appear to be present in microsomes of untreated rats since less than 1% can be recovered as the DEAE-cellulose fraction by this procedure.

Journal ArticleDOI
TL;DR: Differential thermal inactivation of the flavin-containing monooxygenase totally abolishes phenylthiourea S-oxidase activity of hamster liver microsomes and appears completely independent from cytochrome P-450.

Journal ArticleDOI
TL;DR: The current data are compatible with a regulatory mechanism in which LDL inhibits cholesterol synthesis in fibroblasts at two points: at the level of 3-hydroxy-3-methylglutaryl coenzyme A reductase, thereby inhibiting mevalonate synthesis, and at one or more points distal to the last intermediate common to the cholesterol and ubiquinone-10 biosynthetic pathways.

Journal ArticleDOI
TL;DR: Cation-induced changes in room temperature fluorescence intensity and low temperature chlorophyll fluorescence emission spectra, and cation regulation of the quantum yield of photosystem I and II partial reactions at limiting light were lost following the trypsin-induced alteration of the LHC.

Journal ArticleDOI
TL;DR: Equations are developed which are applicable when the enzyme is only partially activated by CO 2 and Mg 2+ and the response of carboxylase velocity to CO 2 concentration is sigmoidal when Mg2+ concentration is low.

Journal ArticleDOI
TL;DR: The results of these experiments indicate that chemiluminescence initiated in hepatic microsomes by either NADPH or ascorbate is directly proportional to lipid peroxidation.

Journal ArticleDOI
TL;DR: In this article, Nifurtimox (a nitrofuran derivative) was added to trypanosoma cruzi culture (epimastigote) to induce an increase in the respiratory rate and the release of H 2 O 2 from the whole cells to the suspending medium.

Journal ArticleDOI
TL;DR: It appears that the native enzyme contains two subunits not separable on polyacrylamide gels, only one of which possesses covalently linked flavin.

Journal ArticleDOI
TL;DR: The results suggest that the α-chains in α1(I)-trimer are the same gene products as α1 in type I collagen, but that the co- translational or post-translational hydroxylation of lysyl residues is more extensive in α2(I-trimer.

Journal ArticleDOI
TL;DR: The mode of stimulation of human erythrocyte Ca2+-Mg2--ATPase by calmodulin appears similar to that of Ca2-dependent adenylate cyclase and phosphodiesterase.

Journal ArticleDOI
TL;DR: Stochichiometric binding constants can be assigned unambiguously without making any assumption regarding the nature of the interactions among binding sites, and are illustrated concretely by analyses of binding measurements for several different proteins containing two to six sites.

Journal ArticleDOI
TL;DR: Bornyl pyrophosphate synthetase is the first monoterpene synthet enzyme to be isolated free from competing phosphatases, and the first to show a strong preference for geranyl pyroph phosphate as substrate.

Journal ArticleDOI
TL;DR: A full understanding of the function of the eucaryotic DNA polymerases now depends on the clarification of the intimate mechanisms of DNA synthesis in various modes as discussed by the authors, and identification of the accessory proteins, cofactors, and replicative DNA structures within a given replication complex, as has been accomplished in certain procaryotes (53), may help in this task.

Journal ArticleDOI
TL;DR: Correlation of inhibitor constants with chemical and physical properties showed a dependence on the softness of the metal ion as an acid and also a dependenceon ionic size.

Journal ArticleDOI
TL;DR: Proteoglycans of calf and steer articular cartilage were studied with a view of assessing structure and changes occurring as a result of the aging process and showed a maturation-related decrease in chondroitin sulfate content and an enrichment in keratan sulfate chains in both the chondrodynamically larger and smaller keratan sulphate-rich regions.