Acid-base phosphorylation

Recently the kinetics of acid base phosphorylation was studied using rapid mixing and quenching techniques [44,46]. In contrast with post-illumination phospho- 

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When the rate of ATP synthesis is plotted versus the total electrochemical gradient which serves as its driving force, a non-linear curve is obtained with little or no ATP synthesis until a threshold value of about 120-150 mV is reached, and a close to linear dependence thereafter. This behavior has been demonstrated in all of the ATP-synthesizing systems photophosphorylation, post-illumination phosphorylation and acid-base phosphorylation, and under a variety of energy-limiting conditions such as light intensity, inhibitors, uncouplers, etc. 

The results of experiments on acid-base phosphorylation (the pH jump-induced ATP synthesis) performed by isolated or membrane-bound H ATPases could be interpreted on the basis of the relaxation concept of enzyme catalysis. This concept allows us to suggest a model for ATP synthesis consistent with all the experimental data considered above. It has been proposed, in [182-187, 190, 191], that the fast ionization of certain acid... 

Phosphoric Acid-Based Systems for Cellulosics. Semidurable flame-retardant treatments for cotton (qv) or wood (qv) can be attained by phosphorylation of cellulose, preferably in the presence of a nitrogenous compound. Commercial leach-resistant flame-retardant treatments for wood have been developed based on a reaction product of phosphoric acid with urea—formaldehyde and dicyandiamide resins (59,60). 

Aspirin in doses used to treal rheumatoid arthritis can result in uncoupling of oxidative phosphorylation, increased oxygen consumption, depletion of hepatic glycogen, and the pyref c effect of toxic doses of salicylate. Depending on the degree of salicylate intoxication, the symptoms can vary from tinnitus to pronounced CNS and acid-base disturbance. 

A mechanistic study of acetophenone keto-enol tautomerism has been reported, and intramolecular and external factors determining the enol-enol equilibria in the cw-enol forms of 1,3-dicarbonyl compounds have been analysed. The effects of substituents, solvents, concentration, and temperature on the tautomerization of ethyl 3-oxobutyrate and its 2-alkyl derivatives have been studied, and the keto-enol tautomerism of mono-substituted phenylpyruvic acids has been investigated. Equilibrium constants have been measured for the keto-enol tautomers of 2-, 3- and 4-phenylacetylpyridines in aqueous solution. A procedure has been developed for the acylation of phosphoryl- and thiophosphoryl-acetonitriles under phase-transfer catalysis conditions, and the keto-enol tautomerism of the resulting phosphoryl(thiophosphoryl)-substituted acylacetonitriles has been studied. The equilibrium (388) (389) has been catalysed by acid, base and by iron(III). Whereas... 

In 2006, Yamamoto and Nakashima picked np on this and designed a chiral A -triflyl phosphoramide as a stronger Brpnsted acid catalyst than the phosphoric acids based on this concept. In their seminal report, they disclosed the preparation of new chiral BINOL-derived A -triflyl phosphoramides and their application to the asymmetric Diels-Alder (DA) reaction of a,p-unsaturated ketones with sily-loxydienes [83], As depicted in Scheme 59, chiral A-triflyl phosphoramides of the general type 4 are readily synthesized from the corresponding optically active 3,3 -substituted BINOL derivatives 142 through a phosphorylation/amidation route. 

Cytosine, thymine, and uracil are pyrimidines along with adenine and guanine they account for the five nucleic acid bases. Pyrimidines are heterocyclic single-ringed compounds based on the structure of pyrimidine. Cytosine, thymine, and uracil, like adenine and guanine, form nucleosides and nucleotides in RNA and DNA. When the bases combine with ribose, a ribo-nucleoside forms and when it attaches to deoxyribose, a deoxyribosenucleoside is formed. Names of the nucleoside are summarized in Table 29.1. These in turn combine with phospho-ryl groups, in a process called phosphorylation, to form their respective nucleotides that form nucleic acids. The nucleotides can be tri, di, and mono phosphate nucleotides similar to the way in which adenine forms ATP, ADP, and AMP. 

Jagendorf, A.T. (1967) Acid-base transitions and phosphorylation by chloroplasts. Fed. Proc. 26, 1361-1369. 

PKC is one member of a femily of serine and threonine kinases - so-called because they catalyse the phosphorylation fix)m ATP of serine and threonine amino acid bases found in many different proteins. PKC is distinguished from other protein kinases because it is dependent on Ca and also the phospholipid phosphatidylserine (PS) for activity. When DAG appears free in the plasma membrane, quiescent PKC translocates from the cytosol to the plasma membrane, binding at sites rich in PS. It is this binding of PKC to membrane PS, in the presence of DAG, which confers increased Ca sensitivity to the enzyme and allows release of the catalytic subunit of PKC into the cytosol where target protein phosphorylation... 

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