Abstract
The distances and orientations among the C5‘ methyl group of 5‘-deoxyadenosine, the radical-bearing C1 carbon of the substrate radical, and the low spin (S=1/2) CoII in cob(II)alamin in the active site of coenzyme B12-dependent ethanolamine deaminase from Salmonella typhimurium have been characterized in the CoII-substrate radical pair state by using two-pulse X-band electron spin−echo electron paramagnetic resonance (ESE-EPR) and electron spin−echo envelope modulation (ESEEM) spectroscopies in the disordered solid state. Our approach is based on the orientation-selection created in the EPR spectrum of the biradical by the axial electron−electron dipolar interaction. Simulation of the ESE-EPR line shape yielded CoII-radical exchange and dipole interaction terms, which were used to calculate the CoII-C1 distance of 11.1 A and the dependence of the EPR line shape on the angle between the CoII-C1 axis and the magnetic field vector. ESEEM spectroscopy performed at four magnetic field values addressed the coup...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.