In vitro effects of peroxynitrite treatment on fish liver catalase activity

作者：Sivrikaya Aybike; Kolayli Sevgi^*; Kucuk Murat; Aliyazicioglu Rezzan

来源：Journal of Enzyme Inhibition and Medicinal Chemistry, 2009, 24(2): 432-436.

DOI：10.1080/14756360802188313

• Fish liver
• catalase activity
• peroxynitrite
• decomposed peroxynitrite
• inhibition

The effect of peroxynitrite (PN), a highly toxic agent, on catalase (CAT) activity in fish liver microsomal homogenates was determined. PN was synthesized by mixing acidic hydrogen peroxide solution with sodium nitrite solution and then adding sodium hydroxide solution into the mixture in order to stabilize the highly labile compound peroxynitrous acid (ONOOH) in peroxynitrite anion form (ONOO-). The effect of PN and decomposed peroxynitrite (DPN), prepared by preincubation with HCl, was monitored by using a constant amount of homogenate containing the CAT enzyme. Significant losses were observed in the CAT activity of fish liver enzyme after treatment with PN and also with DPN products, the inhibitory effect of PN being slightly more pronounced than that of DPN. IC50 values were 5.5 and 8.5M for PN and DPN, respectively. The PN inhibition of CAT activity is due to both the effects of the secondary and decomposition products of PN and its nitration and oxidation effects on the amino acid residues of the enzyme.

• 出版日期2009