Model-free extraction of spin label position distributions from pseudocontact shift data† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6sc03736d Click here for additional data file.
نویسندگان
چکیده
A significant problem with paramagnetic tags attached to proteins and nucleic acids is their conformational mobility. Each tag is statistically distributed within a volume between 5 and 10 Angstroms across; structural biology conclusions from NMR and EPR work are necessarily diluted by this uncertainty. The problem is solved in electron spin resonance, but remains open in the other major branch of paramagnetic resonance – pseudocontact shift (PCS) NMR spectroscopy, where structural biologists have so far been reluctantly using the point paramagnetic centre approximation. Here we describe a new method for extracting probability densities of lanthanide tags from PCS data. The method relies on Tikhonovregularised 3D reconstruction and opens a new window into biomolecular structure and dynamics because it explores a very different range of conditions from those accessible to double electron resonance work on paramagnetic tags: a room-temperature solution rather than a glass at cryogenic temperatures. The method is illustrated using four different Tm DOTA-M8 tagged mutants of human carbonic anhydrase II; the results are in good agreement with rotamer library and DEER data. The wealth of high-quality pseudocontact shift data accumulated by the biological magnetic resonance community over the last 30 years, and so far only processed using point models, could now become a major source of useful information on conformational distributions of paramagnetic tags in biomolecules.
منابع مشابه
Label-free target identification using in-gel fluorescence difference via thermal stability shift† †Electronic supplementary information (ESI) available: Experimental details, NMR spectra, and other materials. See DOI: 10.1039/c6sc03238a Click here for additional data file.
متن کامل
Crystallization-induced dual emission from metal- and heavy atom-free aromatic acids and esters† †Electronic supplementary information (ESI) available. CCDC 1044990 and 1044991. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc00253b Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file.
متن کامل
The use of the Rx spin label in orientation measurement on proteins, by EPR† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5cp04753f Click here for additional data file.
متن کامل
Metal-free di- and tri-fluoromethylation of alkenes realized by visible-light-induced perylene photoredox catalysis† †Electronic supplementary information (ESI) available: Experimental details, spectral data, and crystallographic results. CCDC 1533276 and 1533274. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc01703k Click here for additional data file. Click here for additional data file.
متن کامل
Ground-state dioxygen undergoes metal-free [3 + 2]-annulations with allenes and nitrosoarenes under ambient conditions† †Electronic supplementary information (ESI) available. CCDC 1507477, 1507478, 1510902 and 1540299. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc01770g Click here for additional data file. Click here for additional data file.
متن کامل