[Xplor-nih] Pararestraints help needed

[海 张]

Dear all,
     I want to refine my protein structure using paramagnetism-based constraints (PCS, RDC). The module I used for the calculation is Pararestraints in Xplor. I try to follow those two sample scripts from Dr. Bertini's website. One question to me is that why they define two different tensors (two sets of pseudo atoms) for PCSs and RDCs. As I know, if the PCS is measured by comparison the difference of chemical shifts between diamagnetic and paramagnetic samples. The order tensors for PCS should be the same as that for RDCs.
    The other question is that how to calculate the coefficients for XPCS and XRDC?  If the protein structure is known but the metal ion is unknown, can we just use RDCs to determine the order tensors? What program do you use to calculate the order tensors? I used our own program REDCAT but the definition of the order tensors might be different.
   
   Thank you in advance for your answers 
   
   Hong

       
---------------------------------
 @yahoo.cn 新域名、无限量，快来抢注！
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://dcb.cit.nih.gov/pipermail/xplor-nih/attachments/20071001/46f54223/attachment.html 
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: SpamAssassinReport.txt
Url: http://dcb.cit.nih.gov/pipermail/xplor-nih/attachments/20071001/46f54223/attachment.txt