Hello everyone:
We are calculating the structure of a membrane peptide with two helices linked
with a loop with PISEMA data (chemical shift, dipolar coupling) with dihedral
angle? hydrogen bond restraints for the helical part, we also have some
distance restraints for atoms from both helices.
>From PISEMA experiment we expect to get models with the right tilt angle with
>respect to the membrane normal (i.e., the z-axis), but we got models with a
>variety of tilt angles. For example, we expect to have a tilt angle of 12 to
>17 degrees, but some of the models have tilt angle that is 26, which is way
>too large.
I'm wondering what are the factors that determine the tilt angle of the peptide
in XPLOR calculation.
Thanks.
Jian
