- Tytuł:
- Kinetic studies on the oxidation of nitrite by horseradish peroxidase and lactoperoxidase
- Autorzy:
- Gębicka, Lidia
- Powiązania:
- https://bibliotekanauki.pl/articles/1044450.pdf
- Data publikacji:
- 1999
- Wydawca:
- Polskie Towarzystwo Biochemiczne
- Tematy:
-
lactoperoxidase
nitrite
stopped-flow
horseradish peroxidase - Opis:
- The reaction of nitrite (NO-_2) with horseradish peroxidase and lactoperoxidase was studied. Sequential mixing sopped-flow measeruments gave the following values for the rate constants of the reaction of nitrite with compounds II (oxoferryl heme intermediates) of horseradish peroxidase and lactoperoxidase at pH 7.0, 13.3 ± 0.07 mol^{-1}dm^3s^{-1} and 3.5 ± 0.05 · 10^4mol^{-1}dm^3s^{-1}, respectively. Nitrite, at neutral pH, influenced measurements of activity of lactoperoxidase with typical substrates like 2,2'-azino-bis[ethyl-benzothiazoline-(6)-sulphonic acid] (ABTS), guaiacol or thiocyanate (SCN-). The rate of ABTS and guaiacol oxidation increased linearly with nitrite concentration up to 2.5-5 mmol dm^{-3}. On the other hand, two-electron SCN- oxidation was inhibited in the presence od nitrite. Thus, nitrite competed with the investigated substrates of lactoperoxidase. The intermediate, most probably nitrogen dioxide (*NO_2), reacted more rapidly with ABTS or guaiacol than did lactoperoxidase compound II. It did not, however, effectively oxidize SCN- to OSCN-. NO-_2 did not influence the activity measurements of horseradish peroxidase by ABTS or guaiacol method.
- Źródło:
-
Acta Biochimica Polonica; 1999, 46, 4; 919-927
0001-527X - Pojawia się w:
- Acta Biochimica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł