CCL: Planarity of an amide group
- From: Mariusz Radon <mariusz.radon _ gmail.com>
- Subject: CCL: Planarity of an amide group
- Date: Thu, 31 Dec 2009 16:56:48 +0100
Sent to CCL by: Mariusz Radon [mariusz.radon###gmail.com]
Just few suggestions/questions concerning your question about the non-planarity:
- Do you expect the steric interactions between the aminoacids
residues could be important for the adopted conformation? If your
non-planarity were physical, there must be some reason for it...
- Does the non-planarity remain at any correlated level, even simply
DFT:B3LYP? Or, ideally, DFT+D (with dispersion correction)?
Hope that it can be useful.
Best regards and all the best in New Year 2010,
On Thu, Dec 31, 2009 at 4:11 AM, Sanghwa Han hansh,kangwon.ac.kr
> Sent to CCL by: "Sanghwa Han" [hansh~~kangwon.ac.kr]
> Dear colleagues,
> In Biochemistry textbooks, an amide bond (NH-CO) in a peptide is explained
to be planar.
> But when I optimize a capped amino acid (e.g. ACE-Amino Acid-NME) using
HF/6-31G* for RESP charge derivation, the dihedral HN-CO often deviates from
planarity by as much as 20 degrees.
> Do I need to constrain the HN-CO to 0 degrees to obtain an optimized
structure that is used in a RESP charge derivation?
> Does anybody know if the amide group can be non-planar in experimentally
> Sanghwa Han
> -= This is automatically added to each message by the mailing script =->
Mariusz Radon, PhD student
Department of Theoretical Chemistry
mradon /at/ chemia.uj.edu.pl
(PGP public key available on the website)