Nitric oxide donors activate the cyclo‐oxygenase and peroxidase activities of prostaglandin H synthase

FEBS Letters

Maccarrone, Mauro¹  Putti, Sabrina²  Finazzi Agrò, Alessandro¹ 

[1] Department of Experimental Medicine and Biochemical Sciences, University of Rome ‘Tor Vergata’, Via di Tor Vergata 135, I-00133 Rome, Italy;IDI-IRCCS Laboratory of Biochemistry, University of Rome ‘Tor Vergata’, Via di Tor Vergata 135, I-00133 Rome, Italy

关键词: Cyclo-oxygenase;    Peroxidase;    Nitric oxide;    Arachidonate cascade;    5-;    12-;    15-HPETEs;    5-;    12-;    15-hydroperoxyeicosatetraenoic acids;    NO;    nitric oxide;    PHS;    prostaglandin H synthase;    RP-HPLC;    reversed phase–high performance liquid chromatography;    SDS-PAGE;    sodium dodecyl sulphate–polyacrylamide gel electrophoresis;    SNAP;    S-nitroso-N-acetylpenicillamine;    SNP;    sodium nitroprusside;    SPER/NO;    spermine NONOate;    TMPD;    N;    N;    N′;    N′-tetramethyl-p-phenylenediamine;   

DOI  :  10.1016/S0014-5793(97)00643-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Prostaglandin H synthase (PHS) is a dual enzyme with cyclo-oxygenase and peroxidase activities. The nitric oxide (NO) donors, sodium nitroprusside (SNP), S-nitroso-N-acetylpenicillamine (SNAP) and spermine NONOate (SPER/NO), activated both cyclo-oxygenase and peroxidase activities of PHS. SNP activated PHS by increasing V _max without affecting K _m, the activation constants being 1.0 mM for cyclo-oxygenase and 1.3 mM for peroxidase. Analysis of progress curves and absorption spectra of PHS suggested that NO released from SNP interacted with the heme at the active site of the enzyme. Moreover, SNP counteracted the peroxide-induced inactivation of PHS, suggesting that the interplay between the intracellular peroxide and NO is critical in tuning PHS activity in cells.

【 授权许可】

Unknown