Paraoxonase (PON1) is working in vivo in a particular dynamic environment including HDL particles and associated molecules. To decipher the respective and/or concomitant role of the different cofactors involved in this molecular organization, an approach using multiple experimental techniques based on capillary electrophoresis and classical kinetics or kinetics under high pressure was implemented. The effects of calcium and phosphate as protein or plasma cofactor, of human phosphate binding protein (HPBP) as enzyme chaperone, and of a PON1 inhibitor as an active site stabilizer, on the catalytic activities and functional oligomerization of PON1 were scrutinized. PON1 displays two distinct catalytic behaviors, one against esters and lactones, the other against organophosphorus compounds; its functional states and catalytic activities against these substrates are differently modulated by the molecular environment; PON1 exists under several active multimeric forms; the binding of HPBP amends the size of the oligomeric states and exerts a stabilizing effect on the activities of PON1; PON1 functional properties are modulated by HPBP, calcium and phosphate. This integrative approach using several optimized analytical techniques allowed performing comparison of catalytic properties and oligomeric states of functional PON1 in different enzyme preparations. Relevance of these data to understand in vivo physiological PON1 functioning is mandatory.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences|
|State||Published - May 15 2010|
Bibliographical noteFunding Information:
The authors thank Dr. Dan S. Tawfik (The Weizmann Institute of Science, Rehovot, Israel) for providing the mammalian rPON1-G3C9. This work was supported by DGA contract (PEA 010807 ) to P.M. D.R. is under contract with the German Bundesministerium der Verteidigung (M/SABX/8A001).
- Capillary electrophoresis
- Functional stability
- High hydrostatic pressure
- Human phosphate binding protein