Acyl phosphatase and

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

As well as complexing the substrate to the active site, many enzymes link covalently with the substrate, or a portion of it, to form an additional intermediate. Such intermediates occur in the action of enzymes as diverse as alkaline phosphatase (phosphoryl enzyme), serine and cysteine proteases (acyl enzymes), glycosidases (acylal enzymes) and aldolases. 

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. 

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)... 

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