The paramagnetic pseudo-contact shift (PCS) occurs in molecules containing tighly bound rapidly relaxing paramagnetic metal ions such as lanthanides ( 00JACS4154 and 02EJIC2121 ) or certain transition metals such as iron and cobalt. Usually, two components can contribute to the paramagnetic shift, a scalar contact shift (through bond), which propagates about five to six bonds from the paramagnetic center, and a dipolar pseudocontact shift (through space).
Inclusion of paramagnetic shifts as constraints in structure determination ( 95PSC296-4 , 97BIO9867 , 97EJB721-244 , 98JB553-12 , 99JACS9276 , 00BIO5355 ). Use of the site-directed spin-labeling. Examples of PCS on paramagnetic proteins: The use of chemical shift temperatures ( 00JB167 ) Measurement of dipolar couplings in paramagnetic proteins ( 98JACS12903 , 00JPCB2559; 00JB295, 00JB347 and 02JACS5581) to determine the magnetic susceptibility anisotropy. Use of PCS and RDCs or other NMR restraints after introduction of a paramagnet binding site (04JB205-28 and 04JACS2963) A comparative study of the paramagnetism-based constraints vs classical restraints in solution structure determinations of paramagnetic metalloproteins has been described. These constraints are presudocontacts shifts, residual dipolar couplings and nuclear relaxation enhancements. ( 01JB85-21 and 02JB123-22 ) Introduction of a paramagnetic probe to disrupt the symmetry of symmetric protein dimers ( 02JB143-24 ). Relaxation: Incorporation of NMR restraints in Xplor-NIH ( 04JB249 )