Continuous monitoring of ATP-converting reactions by purified firefly luciferase

Lundin, Arne; Rickardsson, Anne; Thore, Anders

doi:10.1016/0003-2697(76)90116-0

Cited by 299 publications

(98 citation statements)

References 13 publications

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“…Secretion of ATP (lower traces) was measured by the firefly luminescence assay, with the gaini of the instrument set so that maximum release with thrombin gave half:chart deflection (indicated by MAX). The decrease in the signal seen at the end of some curves does not represent uptake o0 metabolism of ATP by platelets, but is due to the well-known propertN of the assay system to show a decay in luminescence (23,24). Aggregation (uppem traces) was measured simultaneously in the same cuvette, with the limit set with platelet-free plasma (PFP, as indicated.…”

Section: Methodsmentioning

confidence: 99%

Interrelations of Platelet Aggregation and Secretion

Charo¹,

Feinman²,

Detwiler³

1977

J. Clin. Invest.

338

117

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A B S T R A C T The mechanism of stimulus-response coupling in human platelets was investigated with a new instrument that simultaneously monitors aggregation and secretion in the same sample of plateletrich plasma. When platelets were stimulated by high concentrations of ADP, secretion began only after aggregation was almost complete. With lower concentrations of ADP or with epinephrine, biphasic aggregation was observed, and secretion began simultaneously with, or slightly after, the second phase of aggregation. When platelets were stimulated with high concentrations of y-thrombin or A23187, secretion and aggregation began essentially together. With very low concentrations of y-thrombin or A23187, biphasic aggregation was observed with secretion paralleling the second phase. At every concentration of collagen, secretion and aggregation appeared to be parallel events. Under every condition where the beginning of secretion lagged behind aggregation, secretion was dependent upon aggregation and was inhibited by indomethacin; this is referred to as aggregation-mediated platelet activation. When secretion began at the same time as aggregation, it also occurred in the absence of aggregation and was not blocked by indomethacin; this is referred to as directly induced platelet activation. These observations are -consistent with a simple model of platelet stimulusresponse coupling that includes two mechanisms for activation; aggregation-mediated activation is inhibited by indomethacin, while direct activation does not depend upon aggregation and is not inhibited by indomethacin. Secretion and second wave aggregation appear to be parallel events, with little evidence for second wave aggregation being a consequence of secretion as usually described.

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Section: Methodsmentioning

confidence: 99%

Interrelations of Platelet Aggregation and Secretion

Charo¹,

Feinman²,

Detwiler³

1977

J. Clin. Invest.

338

117

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“…The supernatants were neutralized by 2 M KOW0.3 M Mops and the potassium perchlorate was removed. ATP and ADP contents were measured directly in the supernatants by bioluminescence assays (Lundin et al, 1976) with a luminometer 1250 (LKB Wallace).…”

Section: Cellular Atp/adp Ratio Determinationmentioning

confidence: 99%

Interactions between glucose metabolism and oxidative phosphorylations on respiratory‐competent Saccharomyces cerevisiae cells

Beauvoit

Rigoulet

Bunoust

et al. 1993

European Journal of Biochemistry

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The purpose of this work was to analyze the interactions between oxidative phosphorylations and glucose metabolism on yeast cells aerobically grown on lactate as carbon source and incubated in a resting cell medium. On such respiratory-competent yeast cells, four different metabolic steady states have particularly been studied: (a) glucose feeding under anaerobiosis, (b) ethanol supply under aerobiosis, (c) glucose supply under aerobiosis and (d) glucose plus ethanol under aerobiosis. For each condition, we measured: (a) the cellular ATP/ADP ratio and NADH content sustained under these conditions, (b) the glucose consumption rate (glucose conditions) and the respiratory rate (aerobic conditions).Under aerobic conditions, when ethanol is used as substrate, the ATP/ADP ratio and NADH level are very high as compared with glucose feeding. However, the rate of oxygen consumption is similar under both conditions. The main observation is a large increase in the respiratory rate when both glucose and ethanol are added. This increase corresponds to an ATP/ADP ratio and a NADH level lower than those observed with ethanol but higher than those with glucose. Therefore the response of the respiratory rate to the ATP/ADP ratio depends on the redox potential. We studied the way in which the ATP-consuming activity was increased under glucose + ethanol conditions. By NMR experiments, it appears that neither the futile cycle at the level of the phosphofructo-lkinase/fructo-l,6-bisphosphatase couple nor the synthesis of carbohydrate stores could account for the increase in oxidative phosphorylation. However, it is shown that, in the presence of glucose + ethanol, ATP consumption is strongly stimulated. It is hypothesized that this consumption is essentially due to the combination of the well-known plasma membrane proton-ATPase activation by glucose and the high phosphate potential due to oxidative ethanol metabolism. While it is well documented that oxidative phosphorylations inhibit the glycolytic flux, i.e. the Pasteur effect, we clearly show in this work that the glycolytic pathway limits the ability of mitochondria to maintain a cellular phosphate potential.Studies on isolated mitochondria have demonstrated that the ATP synthesis flux coupled to respiratory rate is controlled by the intramitochondrial phosphate potential value according to both the presence and the nature of the intra-or extramatricial ADP-regenerating system (Kuster et al

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“…ATP and ADP were determined using the firefly luciferase assay [16]. For calibration, internal standards had to be used due to the quenching influence of dimethylsulfoxide.…”

Section: Internal Atp and Adp Concentrationmentioning

confidence: 99%

Uptake of glutamate in Corynebacterium glutamicum

Krämer

Lambert

1990

European Journal of Biochemistry

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The inducible glutamate uptake system in Corynebacterium glutamicum (Krämer, R., Lambert, C., Hoischen, C. & Ebbighausen, H., preceding paper in this journal) was characterized with respect to its mechanism and energy coupling. All possible secondary active uptake mechanisms can be excluded. Glutamate transport is not coupled to the translocation of H+, Na+ or K+ ions. Although changes in membrane potential and uptake activity cannot completely be separated, no correlation between these two parameters is observed. The uptake of glutamate resembles a primary active, ATP‐dependent transport mechanism in several respects. (a) The substrate affinity is very high (1.3 μM). (b) Accumulation of glutamate reaches values of greater than 2 · 105, at least as high as those reported for binding‐protein‐dependent systems in Gram‐negative bacteria. (c) The uptake is unidirectional. Even after complete deenergization, the accumulation ratio was not significantly reduced. (d) The rate of glutamate uptake is directly correlated to the cytosolic ATP content and also to the ATP/ADP ratio. This is shown by varying internal ATP by different procedures applying inhibitors (NaCN, dicyclohexyl carbodiimide), uncouplers (carbonyl m‐chlorophenylhydrazone), ionophores (valinomycin), and even by shifting the cells to anaerobiosis. Uptake is not promoted by cytosolic ATP levels below 1.5 mM, the maximum uptake rate is reached at 4–5 mM ATP.

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Continuous monitoring of ATP-converting reactions by purified firefly luciferase

Cited by 299 publications

References 13 publications

Interrelations of Platelet Aggregation and Secretion

Interrelations of Platelet Aggregation and Secretion

Interactions between glucose metabolism and oxidative phosphorylations on respiratory‐competent Saccharomyces cerevisiae cells

Uptake of glutamate in Corynebacterium glutamicum

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