For POTEntial=3DPO, a restraining function for 3D NOE-NOE
experiments is used.
The intensity of a 3D NOE-NOE crosspeak,
,
between spins , and , is
proportional to the product of the individual NOE transfer
efficiencies of each mixing time:
|
(20.14) |
where is the first and the second mixing time,
R the cross-relaxation matrix, the
equilibrium magnetization of spins , and a constant.
The 3D NOE-NOE intensity can be approximated by
|
(20.15) |
where and are the distances between spins and ,
respectively, and the proportionality constant is set equal to one.
The 3D NOE-NOE function is given by
|
(20.16) |
where is the energy constant specified
by the SCALe statement, is the
observed NOE-NOE intensities, and
are error bounds, and is a scale factor specified by
the RSWITch statement. The NOE-NOE connectivity
and the
intensity and error-bound information are provided by
a pair of ASSIgn statements:
The first ASSIgn statement specifies spins and , along
with the observed intensity and the
error bounds and . The second ASSIgn
statement specifies spins and ; the three real numbers
following the second selection are irrelevant and can be set
to arbitrary values.
Note: the 3D NOE-NOE function can be used in combination with
R-6 or center averaging. For further details, the reader is referred
to
Habazettl et al.
(1992b,a)
and Bernstein et al. (1993).
Xplor-NIH 2023-11-10