PROTON SPIN RELAXATION BY PARAMAGNETIC MOLECULAR OXYGEN

Proton Relaxation Times in Paramagnetic Solutions. Effects of Electron Spin Relaxation

Protein docking using an ensemble of spin labels optimized by intra-molecular paramagnetic relaxation enhancement.

Paramagnetic NMR is a useful technique to study proteins and protein complexes and the use of paramagnetic relaxation enhancement (PRE) for this purpose has become wide-spread. PREs are commonly generated using paramagnetic spin labels (SLs) that contain an unpaired electron in the form of a nitroxide radical, with 1-oxyl-2,2,5,5-tetramethyl-2,5-dihydropyrrol-3-ylmethyl methane thiosulfonate (M...

Electron paramagnetic resonance and proton relaxation rate studies of spin-labeled creatine kinase and its complexes.

A spin-labeled derivative of rabbit muscle creatine kinase has been prepared by reaction of the essential sulfhydryl group at the active sites with a stoichiometric amount of the nitroxide radical N-( I-oxyl-2,2,5,5-tetramethyl-d-pyrrolidinyl) iodoacetamide. The spin-labeled enzyme retains the ability to bind nucleotide substrates although it lacks the phosphotransferase and ATPase activities o...

Proton Spin Relaxation Induced by Quantum Tunneling in Fe8 Molecular Nanomagnet

The spin-lattice relaxation rate T 1 and NMR spectra of H in single crystal molecular magnets of Fe8 have been measured down to 15 mK. The relaxation rate T 1 shows a strong temperature dependence down to 400 mK. The relaxation is well explained in terms of the thermal transition of the iron state between the discreet energy levels of the total spin S = 10. The relaxation time T1 becomes temper...

Proton and Fluorine Spin - Lattice Relaxation in

The spin-lattice relaxation times F, ('H) and 7, (l9F) in CoSiF6 • 6H-.0 have been measured at 30 MHz in the tem­ perature range 150K^F^400 K Both F,('H) and r, (l9F) decrease sharply at the phase transition tempera­ ture of 246 K (cooling cycle). The main relaxation mecha­ nism is assumed to be an Orbach process. From the 7", data an average splitting of the Co2+ ground state of about 400 cm"1...