Paraoxonase 1 activity

Aviram, M., Vaya, J., 2013. Paraoxonase 1 activities, regulation, and interactions with atherosclerotic lesion. Curr. Opin. Lipidol. 24 (4), 339-344. 

The A-esterases now classified as diisopropyl fluorophosphatases (diiso-propyl-fluorophosphate fluorohydrolase, DFPase, somanase, EC 3.1.8.2) were previously listed under EC 3.8.2.1. These enzymes, which hydrolyze P-F and P-CN bonds such as those of nerve gases, should be described as organophosphorus acid anhydrolases rather than phosphatases [56]. Diisopropyl-fluoro-phosphatases exist in different forms with contrasting substrate specificities. One form is able to hydrolyze paraoxon at a low rate, while others have no paraoxonase activity. The different forms differ in their molecular weights and in their requirements for bivalent cations for activity [56]. 

Hernandez, A.F., et al. 1993. Characterization of paraoxonase activity in pericardial fluid Usefulness as a marker of coronary disease. Chem Biol Interact 87 173. 

Berkowitz, G.S., J.G. Wetmur, E. Birman-Deych, J. Obel, R.H. Lapinski, J.H. Godbold, I.R. Holzman, and M.S. Wolff. 2004. In utero pesticide exposure, maternal paraoxonase activity, and head circumference. Environ. Health Perspect. 112(3) 388-391. 

Kiyici, A. Okudan, N. Gokbel, H. Belviranli, M. 2010. The effect of grape seed extracts on serum paraoxonase activities in streptozotocin-induced diabetic rats. J. Med. Food 13 725-728. 

Fuhrman, B., Aviram, M. (2002). Preservation of paraoxonase activity by wine flavonoids possible role in protection of LDL from hpid peroxidation. Ann. N.Y. Acad. Sci., 957, 321-324. 

Bryk, B., BenMoyal-Segal, L., Podoly, E., Livnah, O., Eisenkraft, A., Luria, S., Cohen, A., Yehezkelli, Y., Hourvitz, A., Soreq, H. (2005). Inherited and acquired interactions between AChE and PONl polymorphisms modulate plasma acetylcholinesterase and paraoxonase activities. J. Neurochem. 92 1216-27. 

Josse, D., Xie, W., Masson, P., Schopfer, L.M., Lockridge, O. (1999b). Tryptophan residue(s) as major components of the human serum paraoxonase active site. Chem. Biol. Interact. 119-20 79-84. 

Li et al., 2000). The most surprising observation was that PONl null mice did not show an increased sensitivity to paraoxon, the substrate after which the enzyme was named, in spite of having no paraoxonase activity in plasma and fiver (Li et al., 2000). 

A similar study in a group of 152 UK Gulf War veterans, who self-reported the presence of symptoms associated with the Gulf War Syndrome, yielded somewhat different results (Mackness et al, 2000). Plasma paraoxonase activity and levels of PONl protein were lower in veterans than in a control group, and these decreases were independent of the PONl genotype (Mackness et al, 2000). Thus, while in both... 

Leviev, I., James RW. (2000). Promoter polymorphisms of human paraoxonase PONl gene and serum paraoxonase activities and concentrations. Arterioscler. Thromb. Vase. Biol. 20 516-21. 

Similar results have been reported for polymorphisms at amino acid 55, with the PONl paraoxonase activity in blood serum from 55M (methionine) homozygotes reduced compared to either the 55L (leucine) homozygotes or the LM heterozygotes (Mackness et al, 1997). While it is intuitive that the rate of detoxification of a substrate would be dependent on the expression levels of these endogenous enzymes, the effects of the genetic polymorphisms suggest that catalytic efficiency is an equally important consideration. 

T. F. Dantoine, J. Debord, J. P. Charmes, L. Merle, P. Marquet, G. Lachatre and C. Leroux-Robert, Decrease of Serum Paraoxonase Activity in Chronic Renal Failure, Journal of American Society of Nephrology 9(11) (1998) 2082-2088. 

Aviram, M., Billecke, S., Sorenson, R., Bisgaier, C., Newton, R., Rosenblat, M., Erogul, J., Hsu, C., Dunlop, C., and La Du, B. 1998, Paraoxonase active site required for protection against LDL oxidation involves its free sulfhydryl group and is different from that required for its arylesterase/paraoxonase activities selective action of human paraoxonase aUozymes Q and R, Arterioscler. Thromb. Vase. Biol., vol. 18, no. 10, pp. 1617-1624. 

Abbott, C.A., Mackness, M.I., Kumar, S., Boulton, A.J., and Durrington, P.N., Serum paraoxonase activity, concentration, and phenotype distribution in Diabetes Mellitus and its relationship to serum lipids and lipoproteins, Aterioscl. Thromb. Vase. Biol, 15,1812-1818, 1995. 

Agachan, B. et al. Paraoxonase 55 and 192 polymorphism and its relationship to serum paraoxonase activity and serum lipids in Turkish patients with non-insulin dependent diabetes mellitus. Cell Biochem. Fund. 22 (2004) 163-8. 

OP insecticide with a structure similar to malathion, which is not a substrate for PON (Li et aL, 2000). As also predicted, PON mice showed a dramatically increased sensitivity to chiorpyrifos-oxon and diazoxon (Shih et ai., 1998 Li et ai, 2000). PONl mice showed an intermediate sensitivity to diazoxon toxicity (Li ef al, 2000). PONl null mice showed only a slight increase in sensitivity to the toxicity of chlorpyrifos and diazinon (Shih et a ., 1998 Li el al., 2000). The most surprising observation was that PONl null mice did not show an increased sensitivity to paraoxon, the substrate after which the enzyme was named, despite having no paraoxonase activity in plasma and liver (Li ei ai. 2000). 

Berkowitz, G. S., Wetmur, J. G, Biman-Deych, E Obel, J, Lapinski, R. H., Godbold, J. H Holzman, I. R and Wolff. M. S, (2(X>4). In wero pesticide expo.sure, maternal paraoxonase activity, and head circumference. E/ivitoh. Health Perspect. 112, 388-391. 

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