Acyl phosphatase

Orthophosphate as substrate or product, ACETATE KINASE (PYROPHOSPHATE) ACETYL-CoA CARBOXYLASE ACID PHOSPHATASE ACTOMYOSIN ATPase ACYL PHOSPHATASE ASPARTATE-SEMIALDEHYDE DEHYDROGENASE ATPases... 

Benitez LV, Allison WS (1974) The inactivation of the acyl phosphatase activity catalyzed by the sulfenic acid form of glyceraldehyde 3-phosphate dehydrogenase by dimedone and olefins. J Biol Chem 249 6234-6243... 

Animal and bacterial enzymes that utilize or synthesize carbamyl phosphate have activity with acetyl phosphate. Acyl phosphatase hydrolyzes both substrates, and maybe involved in the specific dynamic action of proteins. Ornithine and aspartic transcarbamylases also synthesize acetylornithine and acetyl aspartate. Finally, bacterial carbamate kinase and animal carbamyl phosphate synthetase utilize acetyl phosphate as well as carbamyl phosphate in the synthesis of adenosine triphosphate. The synthesis of acetyl phosphate and of formyl phosphate by carbamyl phosphate synthetases is described. The mechanism of carbon dioxide activation by animal carbamyl phosphate synthetase is reviewed on the basis of the findings concerning acetate and formate activation. 

The large concentrations of acyl phosphatase present in most tissues led to the belief that it prevented the demonstration of acetyl-P biosynthesis and accumulation in animal tissues. We purified extensively, some years ago, what- we first thought to be a specific carba-myl-P phosphatase. This enzyme interested us as a tool for better understanding the mechanism of citrulline synthesis however, on testing for specificity, we found that it attacked acetyl-P just as readily as carbamyl-P. 

Table I. Amino Acid Composition of Brain Acyl Phosphatase...

N3 Nassi, P., Cappugi, G., Niccoli, A. and Ramponi, G. Inhibition of horse liver acyl phosphatase by orotic acid. Physiol. Chem. Phys., 5, 109-115 (1973)... 

An accelerated breakdown of high-energy phosphate could readily explain the effect of thyroxine preincubation of canary liver mitochondria with thyroxine enhances ATP breakdown, and thyroxine increases acyl phosphatase activity in liver and muscle. The principles on which these experiments were conducted undoubtedly were sound, yet the relationship between the effect of thyroxine on high-energy phosphates and the physiological role of the hormone remains unsettled. 

D. K+-Dependent Acyl Phosphatase and Cell Membrane Na -I- K -Dependent ATPase... 

Using a cell membrane preparation made from guinea pig liver cortex, Bader and Sen (1966) demonstrated that acetyl phosphate and car-bamyl phosphate were hydrolyzed at a rate dependent on K which was comparable to the Na" -I- K -dependent hydrolysis of ATP. These two hydrolytic activities were closely related with regard to monovalent cation specificity, Michaelis constants, optimal pH, and inhibition by ouabain. Accordingly, fiiey have suggested that an acyl phosphate may be a functional intermediate in the system. Other acyl phosphatases have no cation requirements and are not inhibited by Hg+. ... 

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