Re: [ccp4bb]: monovalent cations in e-density

["Gerard \"DVD\" Kleywegt" <gerard@xray.bmc.uu.se>]

***  For details on how to be removed from this list visit the  ***
***    CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html    ***


K+ has twice the nr of electrons of Na+/NH4+
NH4+ would be expected to donate H-bonds
Na+ see M Nayal & E Di Cera, JMB 256, 228-234 (1996)

the USF program XPAND has a "water scrutiniser" which
looks at surrounding atoms of entities modeled as
water to see if they might be something else

--dvd

> Maybe not CCP4-related, but I am seeking guidance on interpreting
> e-density that appears to arise from monovalent cations -- how to
> differentiate, e.g., Na+, K+, NH4+.  Any relevant references and/or
> programs would be appreciated.

******************************************************************
                        Gerard J.  Kleywegt
Dept. of Cell & Molecular Biology  Bolshevik University of Uppsala
                Biomedical Centre  Box 596
                SE-751 24 Uppsala  SWEDEN

    http://xray.bmc.uu.se/gerard/  mailto:gerard@xray.bmc.uu.se
******************************************************************
   The opinions in this message are fictional.  Any similarity
   to actual opinions, living or dead, is purely coincidental.
******************************************************************