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Updated: May 8, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Dynamic interaction between membrane-bound full-length cytochrome P450 and cytochrome b5 observed by solid-state NMR
Kazutoshi Yamamoto1, Ulrich H N Dürr, Jiadi Xu
1Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055.
Abstract:
Microsomal monoxygenase enzymes of the cytochrome-P450 family are found in all biological kingdoms, and play a central role in the breakdown of metabolic as well as xenobiotic, toxic and 70% of the drugs in clinical use. Full-length cytochrome-b5 has been shown to be important for the catalytic activity of cytochrome-P450. Despite the significance in understanding the interactions between these two membrane-associated proteins, only limited high-resolution structural information on the full-length cytochrome-P450 and the cytochromes-b5-P450 complex is available. Here, we report a structural study on a functional ~72-kDa cytochromes-b5-P450 complex embedded in magnetically-aligned bicelles without having to freeze the sample. Functional and solid-state NMR (Nuclear Magnetic Resonance) data reveal interactions between the proteins in fluid lamellar phase bilayers. In addition, our data infer that the backbone structure and geometry of the transmembrane domain of cytochrome-b5 is not significantly altered due to its interaction with cytochrome-P450, whereas the mobility of cytochrome-b5 is considerably reduced.
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