Adenosine-triphosphate -sensitive

Aguilar-Bryan L, Bryan J (1999) Molecular biology of adenosine triphosphate-sensitive potassium channels. Endocr Rev 20 101-135... 

Tricarico D, Servidei S, Tonali P, Jurkat-Rott K, Camerino DC (1999) Impairment of skeletal muscle adenosine triphosphate-sensitive K+ channels in patients with hypokalemic periodic paralysis. J Clin Invest 103 675-682. 

Jeppesen PB, Gregersen S, Poulsen CR, Hermansen K (2000) Stevioside acts directly on pancreatic (3 cells to secrete insulin actions independent of cyclic adenosine monophosphate and adenosine triphosphate-sensitive K-l—channel activity. Metabolism 49 208-214 Abudula R, Jeppesen PB, Rolfsen SED, Xiao J, Hermansen K (2004) Rebaudioside A potentially stimulates insulin secretion from isolated mouse islets studies on the dose-, glucose-, and calcium-dependency. Metabolism 53 1378-1381... 

The modes of action for niclosamide are interference with respiration and blockade of glucose uptake. It uncouples oxidative phosphorylation in both mammalian and taenioid mitochondria (22,23), inhibiting the anaerobic incorporation of inorganic phosphate into adenosine triphosphate (ATP). Tapeworms are very sensitive to niclosamide because they depend on the anaerobic metaboHsm of carbohydrates as their major source of energy. Niclosamide has selective toxicity for the parasites as compared with the host because Httle niclosamide is absorbed from the gastrointestinal tract. Adverse effects are uncommon, except for occasional gastrointestinal upset. 

Today, bioluminescence reactions are used as indispensable analytical tools in various fields of science and technology. For example, the firefly bioluminescence system is universally used as a method of measuring ATP (adenosine triphosphate), a vital substance in living cells Ca2+-sensitive photoproteins, such as aequorin from a jellyfish, are widely utilized in monitoring the intracellular Ca2+ that regulates various important biological processes and certain analogues... 

Other nuclei, such as 13C or 31P, may be used to study other metabolite pools, or they can complement H-NMR to create more sophisticated NMR spectra. 13C-NMR provides a greater spectral range ( 200 ppm) than H-NMR ( 15 ppm). Although lower natural abundance of 13C (1.1%) yields lower sensitivity, it also provides an opportunity to use isotopic enrichment to trace specific metabolic pathways with enhanced sensitivity.4 31P can observe high-energy phosphate metabolites such as adenosine triphosphate. 

Ozone has been shown to initiate many physiological and biochemical changes in sensitive plant species. Decreases in photosynthesis and increases and decreases in respiration have occurred in response to ozonation. The bioenergetic status of mitochondria and chloroplasts is disturbed by ozone. Decreases in oxidative- and photo- phosphorylation have been reported as have increases in adenosine triphosphate and total adenylate content of plant tissue. The variable physiological responses appear to be related to the stage of symptom development at the time of analysis and to the mode of ozone exposure, viz. in vivo and in vitro. 

The sulfonylurea receptor was identified as an adenosine triphosphate (ATP) sensitive potassium (Katp) channel that is present on the (3-cell membrane surface. Closure of these K tp channels causes (3-cell membrane... 

Schematic illustration of a generalized cholinergic junction (not to scale). Choline is transported into the presynaptic nerve terminal by a sodium-dependent choline transporter (CHT). This transporter can be inhibited by hemicholinium drugs. In the cytoplasm, acetylcholine is synthesized from choline and acetyl -A (AcCoA) by the enzyme choline acetyltransferase (ChAT). Acetylcholine is then transported into the storage vesicle by a second carrier, the vesicle-associated transporter (VAT), which can be inhibited by vesamicol. Peptides (P), adenosine triphosphate (ATP), and proteoglycan are also stored in the vesicle. Release of transmitter occurs when voltage-sensitive calcium channels in the terminal membrane are opened, allowing an influx of calcium. The resulting increase in intracellular calcium causes fusion of vesicles with the surface membrane and exocytotic expulsion of acetylcholine and cotransmitters into the junctional cleft (see text). This step can he blocked by botulinum toxin. Acetylcholine s action is terminated by metabolism by the enzyme acetylcholinesterase. Receptors on the presynaptic nerve ending modulate transmitter release. SNAPs, synaptosome-associated proteins VAMPs, vesicle-associated membrane proteins.

Table 1 summarizes the characteristics of several additional FET enzyme sensors. Enzymatically coupled FETs sensitive to acetylcholine (25), triglyceride (26), adenosine triphosphate (ATP) (40), adenosine diphosphate (ADP) (41), glutamate (27), and threonine (42) have been made. 

Firefly luciferase catalyzes the reaction of adenosine triphosphate and a substituted benzothiazole luciferin. The quantum yield of the reaction is high and therefore measurement of the enzyme offers good sensitivity. Coupling of luciferase to other molecules is a problem because there is a highly reactive amino group in the active site that must be protected from reaction with coupling rei ents (36, 37). 

The kinases are inhibited by pyruvate and adenosine disphosphate (ADP), and the phosphatases are activated by calcium ions. There is normally a constant process of phosphorylation and dephosphorylation of the enzyme, so that it is very sensitive to changes in intraceUular free calcium and the adenosine triphosphate (ATP) ADP ratio. 

---