DAEH N-terminal sequence of avian serum albumins as catalytic center of Cu (II)-dependent organophosphorus hydrolyzing A-esterase activity.

O-hexyl O-2,5-dichlorophenyl phosphoramidate (HDCP) induces delayed neuropathy. The R (+)-HDCP inhibits and caused the so call "aging reaction" on inhibited-NTE. This enantiomer is not hydrolyzed by Ca(II)-dependent A-esterases in mammal tissues but is hydrolyzed by Cu(II)-dependent chicken serum albumin (CSA).

Hydrolysis of chiral organophosphorus compounds by phosphotriesterases and mammalian paraoxonase-1.

Some organophosphorus compounds (OPs), which are used in the manufacturing of insecticides and nerve agents, are racemic mixtures with at least one chiral center with a phosphorus atom. Acute exposure of humans to these mixtures induces the covalent modification of acetylcholinesterase (AChE) and neuropathy target esterase (NTE) and causes a cholinergic syndrome or organophosphate-induced delayed polyneuropathy syndrome (OPIDP). These irreversible neurological effects are due to the stereoselective interaction of the racemic OPs with these B-esterases (AChE and NTE) and such interactions have been studied in vivo, ex vivo and in vitro, using stereoselective hydrolysis by A-esterases or phosphotriesterases (PTEs) and the PTE from Pseudomonas diminuta, and paraoxonase-1 (PON1) from mammalian serum.

Copper(II)-dependent hydrolysis of trichloronate by turkey serum albumin.

Trichloronate is a racemic organophosphonothioate insecticide that induced delayed neuropathic in hens and human. The avian are species with great susceptibility to organophosphorus poisoning due to their low levels of A-esterases. However, a significant copper-dependent A-esterase activity has been identified in chicken and turkey serum.

Copper-dependent hydrolysis of trichloronate by turkey serum studied with use of new analytical procedure based on application of chiral chromatography and UV/Vis spectrophotometry.

Trichloronate is a racemic organophosphate, which has been used for the manufacture of insecticides. This compound induces delayed neuropathy in hen and humans. This study shows the Cu-dependent hydrolysis of trichloronate by turkey serum using UV/Vis spectrophotometry and chiral chromatography.

Paraoxonase-1 polymorphisms and cerebral ischemic stroke: a pilot study in mexican patients.

Background: The serum paraoxonase-1 (PON1) associated to HDL presents two common polymorphisms in the positions 192 and 55. These polymorphisms are considered determinant of the capacity of HDL to protect LDL from their oxidative modification. In this context, the PON1 genotype has been associated with cardiovascular diseases, including stroke.

Relationship Between Paraoxonase-1 and Butyrylcholinesterase Activities and Nutritional Status in Mexican Children.

Background: The enzymes butyrylcholinesterase (BuChE) and paraoxonase-1 (PON1) are the primary bioscavenging enzymes in serum and exhibit antioxidant and anti-inflammatory activities. PON1 has been associated with diseases caused by high oxidative stress, whereas BuChE appears to be involved in the pathophysiology of the metabolic syndrome and related disorders. It has been suggested that children from rural communities in Mexico may have a predisposition to develop obesity or type 2 diabetes during adolescence or adulthood.

Fenamiphos is recalcitrant to the hydrolysis by alloforms PON1 Q192R of human serum.

Fenamiphos (ethyl 4-methylthio-m-tolyl isopropylphosphoramidate) is a racemic organophosphorus nematicide widely used in agriculture around the world. The paraoxonase 1 from human serum (PON1) is a phosphotriesterase (PTE) that hydrolyses several xenobiotics including drugs and organophosphorus compounds (OPs). In this work, the separation of the enantiomers of fenamiphos by HPLC using the column CHIRALCEL OJ and a mobile phase of hexane/ethanol (99/1) is presented.

Relationship between the paraoxonase (PON1) L55M and Q192R polymorphisms and obesity in a Mexican population: a pilot study.

The aim of this study was to examine the relationship between the L55M and Q192R paraoxonase (PON1) polymorphisms and obesity in a population of adult Mexican workers. The study population included 127 adult individuals from the Universidad Autónoma del Estado de Morelos, ranging in age from 20 to 56 years and representing both sexes. Based on body mass index, 63 individuals were classified as obese and 64 as normal weight.