摘要 |
A method for preferentially observing an exposed position ( 1 c) of a macromolecule. A sample is obtained having a macromolecule ( 1 a) with a first proton ( 1 ) and a second molecule ( 2 a) with a second proton ( 2 ); then applying a magnetic field ( 4 ) to the sample and irradiating the sample with a pulse sequence ( 5 ) that preferentially demagnetizes protons of the macromolecule ( 1, 3 ) relative to the second proton ( 2 ); allowing the second proton ( 2 ) to exchange ( 6 ) with an exposed proton ( 1 ) of the macromolecule; and detecting the magnetization from the relatively magnetized second proton ( 2 ), which is now bound to the exposed position ( 1 c) of the macromolecule. The invention also provides a method for observing a position in the macromolecule that bind a ligand. |