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Bis-THF motif of acetogenin binds to the third matrix-side loop of ND1 subunit in mitochondrial NADH-ubiquinone oxidoreductase.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 2011 Sep; Vol. 1807 (9), pp. 1170-6. Date of Electronic Publication: 2011 May 17. - Publication Year :
- 2011
-
Abstract
- Natural acetogenins are among the most potent inhibitors of bovine heart mitochondrial NADH-ubiquinone oxidoreductase (complex I). Our photoaffinity labeling study suggested that the hydroxylated bis-THF ring moiety of acetogenins binds at "site A" in the third matrix-side loop connecting the fifth and sixth transmembrane helices in the ND1 subunit [Kakutani et al. (2010) Biochemistry 49, 4794-4803]. Nevertheless, since this proposition was led using a photoreactive Δlac-acetogenin derivative, it needs to be directly verified using a natural acetogenin-type probe. We therefore conducted photoaffinity labeling using a photoreactive natural acetogenin mimic ([(125)I]diazinylated natural acetogenin, [(125)I]DANA), which has a small photolabile diazirine group, in place of a hydroxy group, attached to the bis-THF ring moiety. Analysis of the photocross-linked protein in bovine heart submitochondrial particles unambiguously revealed that [(125)I]DANA binds to the membrane subunit ND1 with high specificity. The photocross-linking was completely blocked in the presence of just a 5-fold excess of bullatacin, indicating that [(125)I]DANA is an excellent mimic of natural acetogenins and hence binds to the site that accommodates natural products. Careful examination of the fragmentation patterns of the cross-linked ND1 generated by different proteases and their combinations indicated that the cross-linked residue is predominantly located at the supposed site A in the third matrix-side loop.<br /> (2011 Elsevier B.V. All rights reserved.)
- Subjects :
- Acetogenins chemistry
Acetogenins pharmacology
Animals
Cattle
Electron Transport Complex I antagonists & inhibitors
Electrophoresis, Polyacrylamide Gel
Hydrolysis
Photoaffinity Labels
Protein Binding
Submitochondrial Particles enzymology
Acetogenins metabolism
Electron Transport Complex I metabolism
Mitochondria, Heart enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1807
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 21616052
- Full Text :
- https://doi.org/10.1016/j.bbabio.2011.05.012