HOQNO interaction with cytochrome b in succinate:menaquinone reductase from Bacillus subtilis
(1995) In FEBS Letters 359(1). p.23-26- Abstract
- 2-n-Heptyl4-hydroxyquinoline-N-oxide (HOQNO) inhibits the succinate:quinone oxidoreductase activity of isolated and membrane-bound succinate:menaquinone oxidoreductase of B. subtilis. The inhibition pattern resembles closely that observed for α-thenoyltrifluoroacetone and carboxins in the mitochondrial succinate:ubiquinone oxidoreductase: ca. 90% of the activity is highly sensitive to HOQNO (K i ca. 0.2 μM for the isolated enzyme) whereas the rest 10% proves to be resistant to the inhibitor. HOQNO binding is shown to perturb the absorption spectrum of the ferrous di-heme cytochrome b of the B. subtilis succinate:quinone oxidoreductase both in the α and Soret bands. In addition, the inhibitor is shown to bring about a negative shift of E m... (More)
- 2-n-Heptyl4-hydroxyquinoline-N-oxide (HOQNO) inhibits the succinate:quinone oxidoreductase activity of isolated and membrane-bound succinate:menaquinone oxidoreductase of B. subtilis. The inhibition pattern resembles closely that observed for α-thenoyltrifluoroacetone and carboxins in the mitochondrial succinate:ubiquinone oxidoreductase: ca. 90% of the activity is highly sensitive to HOQNO (K i ca. 0.2 μM for the isolated enzyme) whereas the rest 10% proves to be resistant to the inhibitor. HOQNO binding is shown to perturb the absorption spectrum of the ferrous di-heme cytochrome b of the B. subtilis succinate:quinone oxidoreductase both in the α and Soret bands. In addition, the inhibitor is shown to bring about a negative shift of E m of the low-potential heme b. It is suggested that HOQNO interacts with a menasemiquinone binding site near the low-potential heme and suppresses the MQ.−-to-MQH2 step of the quinone reductase reaction but allows partly for the MQ-to-MQ.− transition to occur; dismutation of MQ. formed in the latter reaction to MQ and MQH2 may account for the 10% of the enzyme activity insensitive to HOQNO. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/050f76ab-dad3-4cf3-9290-4e4f50b0cf36
- author
- Smirnova, Irina A. ; Hägerhäll, Cecilia ; Konstantinov, Alexander A. and Hederstedt, Lars LU
- organization
- publishing date
- 1995
- type
- Contribution to journal
- publication status
- published
- subject
- in
- FEBS Letters
- volume
- 359
- issue
- 1
- pages
- 23 - 26
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:0028831032
- ISSN
- 1873-3468
- DOI
- 10.1016/0014-5793(94)01442-4
- language
- English
- LU publication?
- yes
- id
- 050f76ab-dad3-4cf3-9290-4e4f50b0cf36
- date added to LUP
- 2017-07-18 10:10:26
- date last changed
- 2021-10-03 04:04:10
@article{050f76ab-dad3-4cf3-9290-4e4f50b0cf36, abstract = {{2-n-Heptyl4-hydroxyquinoline-N-oxide (HOQNO) inhibits the succinate:quinone oxidoreductase activity of isolated and membrane-bound succinate:menaquinone oxidoreductase of B. subtilis. The inhibition pattern resembles closely that observed for α-thenoyltrifluoroacetone and carboxins in the mitochondrial succinate:ubiquinone oxidoreductase: ca. 90% of the activity is highly sensitive to HOQNO (K i ca. 0.2 μM for the isolated enzyme) whereas the rest 10% proves to be resistant to the inhibitor. HOQNO binding is shown to perturb the absorption spectrum of the ferrous di-heme cytochrome b of the B. subtilis succinate:quinone oxidoreductase both in the α and Soret bands. In addition, the inhibitor is shown to bring about a negative shift of E m of the low-potential heme b. It is suggested that HOQNO interacts with a menasemiquinone binding site near the low-potential heme and suppresses the MQ.−-to-MQH2 step of the quinone reductase reaction but allows partly for the MQ-to-MQ.− transition to occur; dismutation of MQ. formed in the latter reaction to MQ and MQH2 may account for the 10% of the enzyme activity insensitive to HOQNO.}}, author = {{Smirnova, Irina A. and Hägerhäll, Cecilia and Konstantinov, Alexander A. and Hederstedt, Lars}}, issn = {{1873-3468}}, language = {{eng}}, number = {{1}}, pages = {{23--26}}, publisher = {{Wiley-Blackwell}}, series = {{FEBS Letters}}, title = {{HOQNO interaction with cytochrome b in succinate:menaquinone reductase from <em>Bacillus subtilis</em>}}, url = {{http://dx.doi.org/10.1016/0014-5793(94)01442-4}}, doi = {{10.1016/0014-5793(94)01442-4}}, volume = {{359}}, year = {{1995}}, }