Long‐Range‐Distance NMR Effects in a Protein Labeled with a Lanthanide–DOTA Chelate
説明
<jats:title>Abstract</jats:title><jats:p>A two‐thiol reactive lanthanide–DOTA (1,4,7,10‐tetraazacyclododecane‐<jats:italic>N</jats:italic>,<jats:italic>N′</jats:italic>,<jats:italic>N′′</jats:italic>,<jats:italic>N′′′</jats:italic>‐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 {<jats:sup>15</jats:sup>N,<jats:sup>1</jats:sup>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.</jats:p>
収録刊行物
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- Chemistry – A European Journal
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Chemistry – A European Journal 13 (6), 1715-1723, 2007-01-30
Wiley