Adenosine di-phosphate

If the body cells require instant energy (as in exercise), the glucose is supplied with oxygen from the blood and is immediately oxidized on the instructions of a facilitating ADP (adenosine di-phosphate) molecule to release energy ... 

ADP Adenosine di-phosphate, a product which can be used to induce platelet aggregation Adsorption Stuface phenomenon by which molecules of a gas or a liquid are fixed on the stuface of a solid, with various types of bonding... 

ADA and PNP were measured spectrofotometrically in cell free extracts as previously described (3). 5 -N was assayed radiochemi-cally using AMP or CMP as substrate in cell free extracts (6). S -N with AMP as substrate is expressed as that part of total AMP ase activityy which is inhibitable by 20 yM Uy3-methylene-adenosine-di-phosphate. ... 

A mixture of adenosine 5 -di (ppA), tri (pppA), and tetra (p4A) phosphates is formed if adenosine 5 -phosphate (pA) is reacted with phosphoryltriimidazole in aqueous solution (N-ethylmorpholine buffer, pH 7) in the presence of Mg" ions. 791... 

Kinetic studies of the nucleotide analogs, y-phenylpropyl di- and triphosphate, have been undertaken to define the role of the adenosine residue in the chemical and enzymic reactions of adenosine triphosphate. A catalytic function associated with binding of metal ions at the adenine nitrogens has been ascribed to the adenosine moiety in phosphate transfer reactions in which adenosine di- or triphosphates function as the phosphate source109-"2. The pH-rate profile (Fig. 6) for the hydrolysis of -y-phenylpropyl diphosphate... 

Pyridoxal 5 -phosphate and/or adenosine di- and triphosphopyridoxal Lys492 SR Ca-ATPase (- Ca2+) Na+-K+-ATPase H+-K+-ATPase... 

Note that the muscular motive power of the human body (see the introduction to this book) comes from the isothermal hydrolysis of adenosine tri-phosphate to di-phosphate (Atkins, 1995), a wet reaction in which little power is associated with reactant and product handling. Nature has evolved to a position of elegant fuel economy. Nature also has to undertake a complex chemical manufacturing task to provide automated selfmaintenance of the body. Chemical reactions are isothermal at blood temperature, along the same lines as the Regenesys system of Chapter 2. 

Fig. 1.7 Summary of the chemical processes involved in oxygenic photosynthesis. Net inputs are shown in circles and products in rectangles.ADP/ATP = adenosine di/triphosphate NADP/NADPH = nicotinamide adenine dinucleotide phosphate and its reduced form, respectively.

Nucleoside 2 (or 3 ),5 -diphosphates have been isolated by degradation of certain coenzymes, as well as from hydrolyzates of nucleic acids. Adenosine 3, 5 -diphosphate (see p. 320) has been isolated by enzymic hydrolysis of coenzyme A and from active sulfate (adenosine 3 -phosphate 5 -phosphosulfate). Adenosine 2, 5 -diphosphate was shown to be present in the adenylic acid moiety of the coenzyme adenine-nicotinamide dinucleotide phosphate which, by treatment with a 5 -nucleotidase from potatoes, is converted into adenosine 2 -phosphate. Adenosine 3, 5 -di-phosphate is reported to play a role as a cofactor in the bioluminescence of Renilla reniformis (pansy) Ribonucleic acid carrying a terminal 5 -phos-phate group yields ribonucleoside 3, 5 -diphosphates on digestion with phosphoesterases. ... 

PH Decoupling of trialkyl phosphites and phosphates by paramagnetic reagents only occurs when there is direct co-ordination. In most cases 8p is shifted downfield, but h showed no definite trend. The most effective reagent was cobalt chloride in acetonitrile solution. The H-1 proton of dinucleotide mono- and di-phosphates was identified by the broadening of its resonance that occurred upon the addition of Mn + ions. A study of the effects of paramagnetic ions on adenosine 5 -monophosphate has also been reported. ... 

Polymer-supported macrocycles A and B are able to take up nucleotide phosphates such as adenosine di- and triphosphate (ADP and ATP) at pH 4... 

PhP = phenyl phosphate, p-Tyr = 0-phospho-L-tyrosine, MeP = methyl phosphate, diMeP = dimethyl phosphate, ATP = adenosine 5 -triphosphate, ADP = adenosine 5 -di-phosphate, AMP = adenosine 5 -monophosphate, cAMP = adenosine 3, 5 -cyclic monophosphate. 

Hydrogen peroxide produced by reduction of is relatively innocuous and has limited reactivity in the absence of metals. However, in the presence of Fe +, H O produces the very reactive hydroxyl radical (HO ) by the so-called Fenton reaction (see Chapter 13). Iron compounds complexed with phosphate esters (adenosine di- and triphosphate, ADP and ATP) can decompose H O to form free radicals. The presence of the ADP-Fe complex in plant and animal foods may trigger the reduction of H O to form the very reactive and potentially damaging hydroxyl radicals (3). 

Phosphorus has more known fimctions than any other mineral element in the animal body. The close association of phosphorus with calcium in bone has already been mentioned. In addition, phosphorus occms in phosphoproteins, nucleic acids and phosphohpids.The element plays a vital role in energy metabolism in the formation of sugar-phosphates and adenosine di- and triphosphates (see Chapter 9). The importance of vitamin D in calcimn and phosphorus metabolism has already been discussed in Chapter 5. The phosphorus content of the animal body is considerably less than that of calcimn content. Whereas 99 per cent of the calcium found in the body occurs in the bones and teeth, the proportion of the phosphorus in these structures is about 80-85 per cent of the total the remainder is in the soft tissues and fluids, where it serves the essential fimctions mentioned above. The control of phosphorus metabolism is different from that of calcium. If it is in an available form, phosphorus is absorbed well even when there is an excess over requirement. The excess is excreted via the kidney or the gut (via sahva). In monogastric animals, the kidney is the primary route of excretion. Plasma phosphorus diffuses into saliva and in ruminants the large amount of chewing during rumination results in saliva being the major input of phosphorus into the rumen rather than the food. 

High resolution studies " on phosphorylase b have permitted the binding sites of the substrate (o-glucose-l-phosphate), an inhibitor (D-glucose-6-phosphate), and the allosteric effectors adenosine mono- and di-phosphates (AMP and ATP) to be established. For this protein, which is an important example of allosteric control, it was determined that the D-glucose-1-phosphate was bound to a site about 8 A from the pyridoxal phosphate (which is an essential cofactor) and 33 A from the region which binds the adenosine nucleotides. 

The nucleotides which consist of three parts, namely a nitrogenous base, a pentose sugar and a phosphate radical, are a very important group of compounds since one or more of them is involved in virtually every biochemical process. The adenosine di- and tri-phosphates which play an essential part in cellular energy exchanges have a nucleotide-type structure as do many of the coenzymes. Furthermore, nucleotides constitute the monomeric units of which the nucleic acids are composed that is to say nucleic acids are polynucleotides. The nucleic acids which are of two types, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are responsible for directing the synthesis of proteins. They specify the unique sequence of amino acids in any particular protein and consequently should be regarded as primordial molecules on whose existence that of the proteins depends. However, since the synthesis of the nucleic acids depends on enzymes which are themselves proteins, this poses the fundamental evolutionary question as to which came first - the biochemical version of the problem of the chicken and the egg ... 

Di-3,5-dinitrophenyl phosphate is hydrolyzed to orthophosphate, and benzyl 3,5-dinitrophenyl phosphate to benzyl phosphate [26], upon UV irradiation. Also, adenosine has been phosphorylated with di-3,5-dinitrophenyl phosphorochloridate and the two protecting groups removed by irradiation to yield adenosine 5 -phosphate. The photo-initiated hydrolysis is accompanied by almost complete P—0, as opposed to C—O, bond fission. Similarly 3-nitrophenol has been used as a protecting group for the synthesis of the highly reactive Pi, Pi-diethyl pyrophosphate [27] (Fig. 6.10). In this case the group was removed by irradiation in 0.05 M-KOH solution. 

Nucleosides and their Derivatives and Related Compounds.—2 -0-Methyladeno> sine, adenosine 5 -phosphate (an orthorhombic form) and its barium salt, 3-deaza-adenosine, 2, 6-anhydro-l-j8-D-arabinofuranosylcytosine, 5,6-dihydroisocytidine, 5,6-dihydro-2,4-dithiouridine, 2,2 -anhydro-l-a-D-xylo-furanosyluracil, guanosine 5 -phosphate [the copper(n) and cadmium salts ], xanthosine, 6-methylthio-9-jS-D-ribofuranosylpurine, 6-benzyl-amino-9-)8-D-ribofuranosylpurine, 4-amino-5-jS-D-ribofuranosyl-5-azaindole, 2 - (3,4 - di - O - acetyl - 2 - deoxy - - l - erythro - pentopyranosyl) - 5,6 - dimethylbenzo -triazole, and 4,5-bis(carboxymethyl)-3-(2,3-0-isopropylidene-j3-D-erythro-furanosyl)-1 -(4-nitrophenyl)pyrazole. ... 

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