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Hi, sorry but this theory doesn't accord with observation: for non-conjugated acyclic esters in the CSD the RMSD of the C-O torsion about the mean (= 0) is ~ 4.7 deg; for non-conjugated acyclic primary amides it's well known that the RMSD of the C-N torsion is ~ 6.0 deg (mean = -1.0), so on average the ester is actually slightly more planar than the amide. I know this because this is how we obtain torsion weights for ligand dictionaries (not perfect I know but better than nothing!). Cheers -- Ian > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Joel Tyndall > Sent: Thursday, July 13, 2006 9:56 PM > To: [email protected] > Subject: Re: [ccp4bb]: structural basis for amide vs ester hydrolysis? > > *** For details on how to be removed from this list visit the *** > *** CCP4 home page http://www.ccp4.ac.uk *** > > > Its due to the stability of the amide (more stable) compared with the > ester. The C-N bond has partial double bond character and is planar > compared with the single bond of an ester where only the C=O > is planar. > > Regards > > joel > > Mark Matthewson wrote: > > Hi folks, > > > > I was puzzled as I went through the literature and could > not find out > > why many esterases cannot catalyze the cleavage of an amide bond, > > while proteases can hydrolyze esters. Is there a structural > basis why > > an esterase cannot hydrolyze an amide or peptide? > > > > Would greatly appreciate your expertise and help. > > > > Best regards, > > > > Rick > > > > > -------------------------------------------------------------- > ---------- > > Do you Yahoo!? > > Everyone is raving about the all-new Yahoo! Mail Beta. > > > <http://us.rd.yahoo.com/evt=42297/*http://advision.webevents.y ahoo.com/handraisers> > > > -- > Joel Tyndall, PhD > > Lecturer > National School of Pharmacy > University of Otago > PO Box 913 Dunedin 9054 > New Zealand > > Pukenga > Te Kura Taiwhanga Putaiao > Te Whare Wananga o Otago > Pouaka Poutapeta 913 Otepoti 9054 > Aotearoa > > Ph / Waea +64 3 4797293 > Fax / Waeawhakaahua +64 3 4797034 > > > > Disclaimer This communication is confidential and may contain privileged information intended solely for the named addressee(s). It may not be used or disclosed except for the purpose for which it has been sent. If you are not the intended recipient you must not review, use, disclose, copy, distribute or take any action in reliance upon it. If you have received this communication in error, please notify Astex Therapeutics Ltd by emailing [EMAIL PROTECTED] and destroy all copies of the message and any attached documents. Astex Therapeutics Ltd monitors, controls and protects all its messaging traffic in compliance with its corporate email policy. The Company accepts no liability or responsibility for any onward transmission or use of emails and attachments having left the Astex Therapeutics domain. Unless expressly stated, opinions in this message are those of the individual sender and not of Astex Therapeutics Ltd. The recipient should check this email and any attachments for the presence of computer viruses. Astex Therapeutics Ltd accepts no liability for damage caused by any virus transmitted by this email. E-mail is susceptible to data corruption, interception, unauthorized amendment, and tampering, Astex Therapeutics Ltd only send and receive e-mails on the basis that the Company is not liable for any such alteration or any consequences thereof.
