If you send a picture of this stuff to the list, I bet someone may recognize it :)
I think it's called 'distributed computing'. On a more serious note, a pharmacophore matching routine would do what you need, but you'd have to convert from E.D. to a 'blank' pharmacophore with all property parameters set exactly to 1. Unfortunately, I don't know of any non-commercial programs for that stuff... Artem -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Ronaldo Alves Pinto Nagem Sent: Friday, November 30, 2007 7:47 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Unidentified ligand (electron density) found at active site Dear crystallographers, I hope someone could give me a hint to solve this problem. I have collected five datasets from the same protein and all of them, including the highest resolution data set (1.6 angstrons), display at the active site of the enzyme a very clear electron density with boundaries well defined. The problem is that I have already tried to fit all kinds of molecules present in the purification and crystallization conditions and none of them fit well into the density. Here are my questions: Is there any program available that could take a small volume of the electron density map (obviously the unidentified electron density ligand) and try to fit a list of known compounds (a list that I do not have, by the way) for potential ligands? Or, is there any website or program that could give me a list of compounds based only in the backbone of the ligand I could sketch from the density (by backbone I mean the plane shape of the compound - I do not know its atom composition)? I hope someone could help. Thanks Ronaldo.
