Written in English
Study of the unfolded states of proteins lends insight into the protein folding problem. A well-studied system, the unfolded state of the N-terminal drk SH3 domain, has been structurally characterized using NMR spectroscopy and other techniques. The computer program ENSEMBLE (Choy and Forman-Kay, 2001) can model the rapidly-interconverting unfolded state ensemble, based on this experimental data. To extend the constraint types usable by ENSEMBLE, the distance-dependent paramagnetic relaxation enhancement (PRE) was measured on a modified SH3 domain; a small ATCUN motif was added to the domain, which binds a paramagnetic Cu2+ ion. Models that predict the position of the copper atom fit well to the experimental PRE data, and an ENSEMBLE restraint based on PRE values was compatible with other structural information. These results support the utility of ATCUN-derived PRE data for characterization of unfolded states, an important goal in understanding protein structure, stability, and function.
|The Physical Object|
|Number of Pages||133|
The SH3 domain is a distinct motif that, together with SH2, may modulate interactions with the cytoskeleton and membrane. Some signaling and transforming proteins contain SH2 and SH3 domains unattached to any known catalytic element. These noncatalytic proteins may serve as adaptors to link tyrosine kinases to specific target by: The theory has been tested by measuring the PRE rates in three spin-labeled mutants of the drkN SH3 domain in 2M guanidinium chloride. The use of a short, three-residue Cu(2+)-binding sequence, the ATCUN motif, is presented as an approach for extracting long-range distance restraints from relaxation enhancement NMR spectroscopy. Modules that use paramagnetism-based NMR restraints have been developed and integrated in the well known program for solution structure determination Xplor-NIH; the complete set of such modules is called PARArestraints for Xplor-NIH. Paramagnetism-based restraints are paramagnetic relaxation enhancements, pseudocontact shifts, residual dipolar couplings due to Cited by:
Settings. Documentation missing. Restraint Set: Selects the restraint set in which to make new restraint lists. Labelling Scheme: Selects the isotope labelling scheme, if any, to filter restraint possibilities. Shift Match Guide Structure: Selects a structure that can be used to remove distal resonance pairs from distance restraints. Threshold for peak figure-of-merit value, below which. The SH3 domain (Src homology domain 3) has been shown to bind to a proline-rich motif in Kv – see Protein phosphorylation, 4. The ESDV motif is found at the C-terminus of the NMDA receptor subunits NR2A and NR2B (see en Vol. * The paramagnetic nature of a compound is proportional to the number of unpaired electrons in it. Mn 2+ ion has more number of unpaired electrons. Hence MnSO H 2 O shows greater paramagnetic nature. Whereas there is only one unpaired electron in Cu 2+ and hence CuSO H 2 O shows lowest degree of paramagnetism. Conclusion: Correct option. Correlations to residual aliphatic protons are accessible via synchronous evolution of the 15N and 13C chemical shifts, which encode valuable amide−methyl distance restraints. On average, we obtain six restraints per by:
distance distributions between 1HN spins and the paramagnetic center (provided that the characteristic correlation time is known with a reasonable accuracy). The theory has been tested by measuring the PRE rates in three MTSL-tagged mutants of the drkN SH3 domain in 2 M guanidinium chloride. Two modifications introduced into the. reconstruct the distance distributions between 1HN spins and the paramagnetic center (provided that the characteristic correlation time is known with a reasonable accuracy). The theory has been tested by measuring the PRE rates in three spin-labeled mutants of the drkN SH3 domain . Electron spin resonance (ESR) has been used to characterize the paramagnetic defects in TiO 2 powder samples which have been subjected to explosive loading to enhance catalytic activity and preserved for post‐shock study. Two prominent defects are observed in the low temperature ESR powder spectra following peak shock pressures of either 13 or 20 GPa in the copper recovery fixture: Cited by: 5. Distance restraints measurements benefit from methodologies currently developed for small soluble proteins in micro-crystalline state. Recent advances in the field increased the releasing rate of high resolution MP structures, providing unprecedented structural and dynamics information making NMR a powerful tool for structural and functional Cited by: 7.