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Long‐Range‐Distance NMR Effects in a Protein Labeled with a Lanthanide–DOTA Chelate
Author(s) -
Vlasie Monica D.,
Comuzzi Clara,
van den Nieuwendijk Adrianus M. C. H.,
Prudêncio Miguel,
Overhand Mark,
Ubbink Marcellus
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200600916
Subject(s) - lanthanide , dota , chemistry , paramagnetism , chelation , amide , denticity , gadolinium , crystallography , relaxation (psychology) , rotational correlation time , nuclear magnetic resonance , inorganic chemistry , molecule , organic chemistry , ion , crystal structure , social psychology , psychology , physics , quantum mechanics
A two‐thiol reactive lanthanide–DOTA (1,4,7,10‐tetraazacyclododecane‐ N , N′ , N′′ , N′′′ ‐tetraacetic acid) chelate, CLaNP‐3 (CLaNP = caged lanthanide NMR probe), was synthesized for the rigid attachment to cysteine groups on a protein surface, and used to obtain long‐range‐distance information from the { 15 N, 1 H} HSQC spectra of the protein–lanthanide complex. The DOTA ring exhibits several isomers that are in exchange; however, single resonances were observed for most amide groups in the protein, allowing determination of a single, apparent magnetic‐susceptibility tensor. Pseudocontact shifts caused by Yb‐containing CLaNP‐3 were observed for atoms at 15–35 Å from the metal. By using Gd‐containing CLaNP‐3, relaxation effects were observed, allowing distances up to 30 Å from the paramagnetic center to be determined accurately. Similar results were obtained with a Gd–DTPA (diethylene‐triaminepentaacetic acid) chelate, CLaNP‐1, bound in the same bidentate manner to the protein. This study demonstrates that bidentate attachment of a paramagnetic probe enables determination of long‐range distances.