TY - JOUR
T1 - Nitric oxide donors activate the cyclo-oxygenase and peroxidase activities of prostaglandin H synthase
AU - Maccarrone, Mauro
AU - Putti, Sabrina
AU - Finazzi Agrò, Alessandro
PY - 1997/6/30
Y1 - 1997/6/30
N2 - 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-acetyl-penicillamine (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.
AB - 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-acetyl-penicillamine (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.
KW - Arachidonate cascade
KW - Cyclo-oxygenase
KW - Nitric oxide
KW - Peroxidase
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U2 - 10.1016/S0014-5793(97)00643-1
DO - 10.1016/S0014-5793(97)00643-1
M3 - Article
C2 - 9237685
AN - SCOPUS:0030795829
VL - 410
SP - 470
EP - 476
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 2-3
ER -