Patterns of product inhibition for bacterial nitrite reductase.
Patterns of product inhibition for bacterial nitrite reductase.
复制标题
细菌亚硝酸还原酶的产物抑制模式。
DOI：
10.1016/s0006-291x(84)80228-4
复制
发表时间：
1984
影响因子：
3.1
通讯作者：
Timkovich,R
中科院分区：
文献类型：
--
作者：
Dhesi,R;Timkovich,R
Product inhibition has been examined in the turnover kinetics of cytochrome cd1from Pseudomonas aeruginosa (ATCC 19429) and from Paracoccus denitrificans (ATCC 13456). A common characteristic was a decrease in rate during the time course of assays that was not due to substrate depletion or irreversible inactivation. The product of nitrite reduction, nitric oxide (NO), acted as a product inhibitor in anaerobic assays with an apparent Kiof 0.2 μM, but only if the enzyme was first preincubated with NO for 15 min. The enzyme was inhibited by the oxidized form of electron donors and this could account for the decrease in rate during an assay. For the donors hydroquinone, ascorbate, TMPD, and azurin, measured values of the inhibition constant were at least ten fold lower than measured Km's. Cytochromes c as donors demonstrated a complex pattern of product inhibition by the ferric form. Although numerical values of Kiin these cases were not obtained, trends indicated that apparent values would be less than Km.
