Abstract
We are using site-directed spin-labeling (SDSL) and dipolar electron-electron resonance (DEER) to study the structural dynamics of proteins involved in muscle function. Muscle proteins are ideal systems for DEER applications, since these proteins form large dynamic assemblies that are inaccessible to crystallography and NMR. DEER is a pulsed ELDOR technique that detects the spin-spin dipolar interaction as a decay and modulation of a spin echo signal. While the CW EPR spectrum is sensitive only to distances on the order of 1 to 2 nm, DEER is sensitive from 1.5 to 5 nm and more. DEER is sensitive to the width of the distance distribution and can resolve multiple structural populations simultaneously. However, a limitation of DEER is the use of spin probes with flexible linkers, which adds uncertainty to the locations of protein backbone atoms. A bifunctional spin label (BSL), which attaches at position (i, i+4) of a helix, was used to measure the distance between two di-Cys pairs. BSL is rigidly coupled to the protein backbone and is a breakthrough for high resolution measurement of orientation, dynamics, and distance. These distance measurements were compared to conventional labeling of cysteine residues with MSL/MSL pairs.
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.