Adenosine triphosphate site

Two examples where actin polymerization is observed in eukaryotes are in the bacterial pathogens Listeria monocytogenes and Shigella flexneri. The motion that the eukaryote pathogens exhibit is the actin based motility in the cytoplasm of their host. Actin polymerization is known to occur via an insertion polymerization mechanism. The movement is a result of site-directed tread-milling of the actin filaments. This type of movement is classified as a propulsive type motion. The driving force for actin pol)unerization as well as the next motor is the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP). ... 

Alvino CG, Acquaviva AM, Memoli Catanzano AM, Tassi V (1995) Evidence that thyroglobulin has an associated protein kinase activity correlated with the presence of an adenosine triphosphate binding site. Endocrinology 136 3179-3185... 

A variety of sodium coordination is shown in the trihydrate of disodium adenosine triphosphate (ATP) (V) (51). There are four different sites for... 

The activation of adenylyl cyclase enables it to catalyze the conversion of adenosine triphosphate (ATP) to 3 5 -cyclic adenosine monophosphate (cAMP), which in turn can activate a number of enzymes known as kinases. Each kinase phosphorylates a specific protein or proteins. Such phosphorylation reactions are known to be involved in the opening of some calcium channels as well as in the activation of other enzymes. In this system, the receptor is in the membrane with its binding site on the outer surface. The G protein is totally within the membrane while the adenylyl cyclase is within the membrane but projects into the interior of the cell. The cAMP is generated within the cell (see Rgure 10.4). 

Since active transport often requires energy in the form of adenosine triphosphate (ATP), compounds or conditions that inhibit energy production (e.g., iodoac-etate, fluoride, cyanide, anaerobiosis) will impair active transport. The transport of a given compound also can be inhibited competitively by the coadministration of other compounds of sufficient structural similarity that they can compete with the first substance for sites on the carrier protein. 

Sympathetic arc involved in blood pressure regulation and sites where drugs may act to influence the system. A. Receptors on effector cell. 6. Adrenergic varicosity. C. Nicotinic receptors (postganglionic fibers). D. Brainstem nuclei. NTS, nucleus of the tractus solitarii VMC, vasomotor center ACh, acetylcholine NE, norepinephrine a, a-adrenoceptors (3, 13-adrenoceptors P2, P2-purinoceptors ATR adenosine triphosphate. 

The ABLl protein has three SRC-homology domains SHI, SH2, and SH3 (Fig. 1C). The SHI domain is a kinase domain and is organized into an N-lobe and C-lobe with the adenosine triphosphate (ATP)-binding catalytic site positioned between these two lobes. In the BCR portion of the molecule, the coil-motif encoded by the first BCR exon is responsible for dimerization of the BCR-ABLl (11). 

The oxygen formed clearly comes from H20 and not from C02, because photosynthesis in the presence of water labeled with lgO produces oxygen labeled with 180, whereas carbon dioxide labeled with 180 does not give oxygen labeled with 180. Notice that the oxidation of the water produces two electrons, and that the formation of NADPH from NADP requires two electrons. These reactions occur at different locations within the chloroplasts and in the process of transferring electrons from the water oxidation site to the NADP reduction site, adenosine diphosphate (ADP) is converted to adenosine triphosphate (ATP see Section 15-5F for discussion of the importance of such phosphorylations). Thus electron transport between the two photoprocesses is coupled to phosphorylation. This process is called photophosphorylation (Figure 20-7). 

As an example of enzyme action, look in Figure 24.11 at the enzyme hexose kinase, which catalyzes the reaction of adenosine triphosphate (ATP) with glucose to yield glucose-6-phosphate and adenosine diphosphate (ADP). The enzyme first binds a molecule of ATP cofactor at a position near the active site, and glucose then bonds to the active site with its C6 hydroxyl group held rigidly in position next to the ATP molecule. Reaction ensues, and the two products are released from the enzyme. 

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