BACKGROUND Multiple myeloma (MM) is a haematological cancer characterized by clonal proliferation of plasma cells.The aim of this study was to investigate the activity of serum paraoxonase-1 (PON1) and arylesterase (ARE) in multiple myeloma with and without free light chain excretion(FLCe-MM and NFLCe-MM); as well as to investigate possible alterations in oxidative stress parameters. MATERIAL...

Investigations on mammalian serum paraoxonase (PON), now called PON1, started nearly 50 years ago by Aldridge2,3 with the study of its hydrolytic activity with paraoxon and other organophosphates. More recently, '5 years ago, it was established that PON1 is a member multigene family in mammals.4 There are 3 PON genes closely aligned on human chromosome 7 and mouse chromosome 6. Research efforts...

BACKGROUND Paraoxonase 1 (PON1), an esterase that hydrolyzes toxic organophosphates and has antioxidative and antiatherogenic properties, contains a common polymorphism at position 192: glutamine (Q) or arginine (R). The Q and R isoenzymes exhibit different physical and protective properties. We describe 2 methods for quantifying their serum activity levels. METHODS We measured serum hydrolyt...

OBJECTIVES : To investigate the effect of lovastatin therapy and withdrawal on paraoxonase 1 (PON1) and arylesterase (ARE) activities, and low-density lipoprotein cholesterol (LDL-C) susceptibility to oxidation in people with type 2 diabetic nephropathy (T2DN). DESIGN AND METHODS : Lovastatin (20mg/day) was administered to 30 people with T2DN for 90days and then withdrawn for 30days. PON1 and...

Serum paraoxonase 1 (PON1) is a native lactonase capable of promiscuously hydrolyzing a broad range of substrates, including organophosphates, esters, and carbonates. Structurally, PON1 is a six-bladed β-propeller with a flexible loop (residues 70-81) covering the active site. This loop contains a functionally critical Tyr at position 71. We have performed detailed experimental and computationa...

BACKGROUND Paraoxonase 1 (PON1) is an enzyme that detoxifies activated organophosphorus pesticides (OPs) and is also involved in oxidative stress pathways. OBJECTIVES PON1 activity in newborns is lower than in adults, but the ontogeny of PON1 activity is poorly characterized in young children. We examined the effects of age and PON1 genotype on enzyme activity in a birth cohort of Mexican-Ame...

Equilibrium dialysis and Scatchard plots were used to establish that human and rabbit paraoxonases both have two calcium binding sites. Independent-site and stepwise constant analyses were used to calculate a higher affinity site (Kd1) of 3.6 +/- 0.9 x 10(-7) M for human A paraoxonase, and 1.4 +/- 0.5 x 10(-8) M for rabbit paraoxonase, and a lower affinity site (Kd2) of 6.6 +/- 1.2 x 10(-6) M f...

The effect of tricresylphosphate (TCP) was studied in vitro and in vivo on the rat liver and brain enzymes acetylcholinesterase (ACC), butyrylcholinesterase (CHE), arylesterase (ARE), aliesterase (ALI), and the microsomal nicotinamide-adenine dinucleotide phosphate oxidase (NADPH2-oxidase) system. The results show that, in the male rat, TCP given intraperitoneally induces an increase in liver m...