The steady state kinetics of sodium and potassium ion transport adenosine triphosphatase (EC 3.6-l. 3) suggests an activating action of adenosine triphosphate in addition to its action as a phosphate donor. This action might be an acceleration of dissociation of Kf or its congeners from the enzyme. To test this possibility transient kinetics of the phosphoenzyme was investigated. In membranes f...

A procedure was devised to detect and assay uridine 5'-pyrophosphate (UDP)-glucuronic acid pyrophosphorylase in plant extracts. Substrates are UDP-glucuronic acid and (32)P-pyrophosphate, and the (32)P-uridine 5'-triphosphate produced is selectively adsorbed to charcoal. The charcoal adsorption procedure is a modification of that used to determine (32)P-adenosine 5'-triphosphate produced by ade...

Enzymes catalyzing the phosphorylation of adenosine monophosphate by adenosine triphosphate have been found in many tissues, and the adenylate kinases from liver and muscle have been extensively purified and studied (l-3). Yeast extracts also phosphorylated uridine monophosphate and guanosine monophosphate (4), and similar reactions were shown to be present in other tissues (5-7). Recently, Str...

Adenosine acts at many sites to modulate neuronal activity. The purpose of this study was to investigate a possible role for adenosine as a neuromodulator of brainstem cardiovascular control. Microinjections of adenosine (0-2.3 nmol) were made stereotaxically into various brainstem sites. Injection of adenosine into the nucleus tractus solitarii (NTS) produced dose-related decreases in heart ra...

The content of soluble nucleotides in aleurone layers isolated from mature wheat (Triticum aestivum var. Olympic) grain was investigated. The most abundant nucleotides were adenosine triphosphate, uridine triphosphate, and uridine diphosphoglucose. Smaller amounts of guanosine triphosphate, cytidine triphosphate, adenosine diphosphate, and nicotinamide adenine dinucleotide were also identified....

Abstract Mitochondria are essential cellular organelles, which supply eukaryotic cells with the universal energy carrier adenosine triphosphate. These organelles feature a unique double-membrane architecture, is formed by smooth outer membrane and highly folded inner membrane. Harnessing super-resolution light electron microscopy, we investigate role of MICOS, large mitochondrial protein comple...

Intravenous adenosine triphosphate rapidly terminated all 11 episodes of paroxysmal supraventricular tachycardia in 10 patients. Eight patients reported side effects but these resolved within 20 seconds and did not require treatment. Adenosine triphosphate is a suitable agent for the rapid termination of paroxysmal supraventricular tachycardia.