Subject: AW: Histidine

From: [email-masked]
Date: Mon, 25 Mar 2002 07:41:56 +0100

Dear Meena,

the way I do this is to inspect each HIS residue manually and have a look on
the surrounding amino acids in terms of ionization state and hydrogen bond
donor/acceptor capabilities. In many cases you get a good hint about where
to put the proton, especially if you have a GLU or an ASP in hydrogen
bonding distance, there is a good chance, that the HIS will form a salt
bridge, hence it carries protons on both nitrogens. In analogy you can make
a decision to put the proton on N(delta) or N(epsilon) depending on the
closeness of HB donors/acceptors. In cases, where I can not make a clear
estimate, I arbitrarily put the proton on N(delta).

Cheers,

Christian
________________________________________________________________

   Dr. Christian Pilger
   Dept. Chemical Research / Structural Research
   K91-00-10
   Boehringer Ingelheim Pharma KG
   D-88397 Biberach/Germany
   Phone: 07351-545749
   Fax:     07351-5497924
   mailto: [email-masked]