3-D Structure of Serum Paraoxonase 1 Sheds Light on Its Activity, Stability, Solubility and Crystallizability

• Published in: Arhiv za higijenu rada i toksikologiju Vol. 58; no. 3; pp. 347 - 353
• Main Authors: Harel, Michal, Brumshtein, Boris, Meged, Ran, Dvir, Hay, Ravelli, Raimond, McCarthy, Andrew, Toker, Lilly, Silman, Israel, Sussman, Joel
• Format: Journal Article
• Language: English
• Published: Croatia Versita 01.09.2007; Institute for Medical Research and Occupational Health
• Subjects: Animals; Aryldialkylphosphatase - blood; Aryldialkylphosphatase - chemistry; Catalysis; catalytic mechanism; Chemical Phenomena; Chemistry, Physical; crystal-forming variants; Crystallization; directed evolution; Humans; katalitički mehanizam; Molecular Conformation; Thromboxane A2; usmjerena evolucija; varijante koje tvore kristale
• ISSN: 0004-1254; 1848-6312
• DOI: 10.2478/v10004-007-0028-0

Serum paraoxonases (PONs) exhibit a wide range of physiologically important hydrolytic activities, including drug metabolism and detoxification of nerve gases. PON1 and PON3 reside on high-density lipoprotein (HDL) (the "good cholesterol"), and are involved in the alleviation of atherosclerosis. Members of the PON family have been identified not only in mammals and other vertebrates, but also in invertebrates. We earlier described the first crystal structure of a PON family member, a directly-evolved variant of PON1, at 2.2 Å resolution. PON1 is a 6-bladed beta-propeller with a unique active-site lid which is also involved in binding to HDL. The 3-D structure, taken together with directed evolution studies, permitted analysis of mutations which enhanced the stability, solubility and crystallizability of this PON1 variant. The structure permits a detailed description of PON1's active site and suggests possible mechanisms for its catalytic activity on certain substrates. Serumske paraoksonaze (PONs) imaju široki raspon fiziološki važnih hidrolitičkih aktivnosti uključujući metabolizam lijekova i detoksikaciju nervnih plinova. PON1 i PON3 smještene su na lipoproteinima visoke gustoće (engl. high-density lipoprotein; HDL - "dobri kolesterol") i uključene su u ublažavanje ateroskleroze. Članovi skupine PON identificirani su ne samo u sisavaca i drugih kralježnjaka već i kod beskralješnjaka. Prije smo opisali prvu kristalnu strukturu člana PON skupine, direktno razrađenu varijantu PON1 pri rezoluciji 2,2 Å. PON1 je beta-propeler sa šest lopatica s jedinstvenim poklopcem aktivnog mjesta, koji je također uključen u vezanje na HDL. 3-D struktura, gledana zajedno s direktnim razvojnim istraživanjima, omogućila je analizu mutacija koje povećavaju stabilnost, topljivost i kristalizaciju te PON1 varijante. Struktura dopušta detaljan opis aktivnog mjesta PON1 i sugerira moguće mehanizme za njezinu katalitičku aktivnost prema određenim supstratima.