Phosphate burst

As ATP binding to myosin, and ATP hydrolysis, are both faster than the overall observed ATPase rate, the slow step that follows the rapid phosphate burst and that must limit the overall observed ATPase rate must be the release of phosphate, or the release of ADP. The rate at which ADP is released was measured by a displacement technique (Trentham et al., 1972), in which the rate at which ADP bound to S-1 is displaced by ATP was measured. This experiment showed that the rate of ADP release (2 s ) is greater than the overall rate of hydrolysis (0.03 s" ). Thus the release of Pj, and not that of ADP, is rate limiting. 

Ferenczi, M.A. (1986). Phosphate burst in permeable muscle fibers of the rabbit. Biophys. J. 50, 471 77. 

Interaction with fused ammonium nitrate or with metal nitrates, phosphates or sulfates may be explosively violent [1]. Lithium and sodium carbonates may also react vigorously [2], The mixture with magnesium sulfate has been described as a noisy but low power bursting charge for pyrotechny [3],... 

Nitric oxide and eicosanoid synthesis haem synthesis. The importance of the pentose phosphate pathway reduced glutathione in maintaining red cell integrity. The respiratory burst in phagocytes. Clotting and complement enzyme cascades. Metabolism of lipoproteins. 

Hydrolytic Decomposition of Phosphoprotein. The kinetic analysis of phosphate liberation revealed that phosphate is not steadily liberated but that an initial lag period occurs which is followed by a transient burst of phosphate liberation123, 177> 192 This burst has been interpreted as resulting from the accumulation of an acid-labile intermediate arising from an acid-stable precursor. The burst is fol-... 

A wide variety of esters is hydrolyzed with the same Vmax (Table 7.8),37 constant product ratios are found (Table 7.9) stopped-flow studies using p-nitrophenyl phosphate find a burst of 1 mol of p-nitrophenolate ion released per enzyme subunit and the enzyme is covalently labeled by diisopropyl fluorophosphate.38... 

When IRS, isoleucine, tRNA, and [y-32P]ATP (labeled in the terminal phosphate) are mixed in the pulsed quenched-flow apparatus (Figure 7.5), there is a burst of release of labeled pyrophosphate before the steady state rate of aminoacylation of tRNA is reached. This means either that the aminoacyl adenylate is formed before the aminoacylation of tRNA, thus proving the... 

In disagreement with the above indications was the finding of Aldridge et al. (146) that for enzyme which was phosphorylated at pH 5.5 with inorganic phosphate and rapidly mixed with buffer at pH 8.4, the rate of dephosphorylation was twice as fast as the turnover of the enzyme at pH 8.0. Also, transient state kinetic studies by Femley and Walker (99, 110) showed a rapid release (burst) of phenol followed by a steady state release of phenol, only at pH < 7. Thus, these data would seem to indicate that at pH >7 the rate determining step is phosphorylation. 

Zinc(II) and Co(II) are the only cations found to reactivate apophos-phatase to any appreciable extent (120). The Co(II) enzyme follows the same formal mechanism as the native enzyme, but has a lower specific activity (113, 121). It lacks the phosphotransferase activity (113, 119, 121) observed for the native enzyme, for example in Tris buffers. This was taken to imply that the lower activity of the cobalt enzyme is due to a lower rate of phosphorylation, so that this step becomes rate-limiting also below f>H 7 (113). Stopped-flow experiments by Gottesman etal. (121) show, however, that a very fast burst of -nitrophenol occurs in the cobalt alkaline phosphatase-catalyzed hydrolysis of -nitrophenyl phosphate over a wide pH region. These results strongly suggest that a step subsequent to the phosphorylation is rate-limiting in this metal derivative. 

Ravichandran V, Seres T, Moriguchi T, Thomas J A, Johnston RB, Jr. 1994. S-thiolation of glyceraldehyde-3-phosphate dehydrogenase induced by the phagocytosis-associated respiratory burst in blood monocytes. J Biol Chem 269 25010-25015. 

Videler and Weihs, 1982). Dunn and Johnston (1986) observed that the first short burst of swimming of Antarctic fish is fuelled by creatine phosphate. Each energy substrate in fish has specific functions that allow diversity in locomotory activity. 

Trusevich, V.V. and Anninsky, B.E. (1987). Macroerg phosphate compounds in fish muscle during burst swimming (In Russian). In Proceedings of 1st Symposium on Ecological Biochemistry of Fish , Yaroslavl Polytechnic Institute Publishing House, pp. 192-194. 

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