> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Sanishvili, Ruslan > Sent: 17 June 2008 22:17 > To: Nave, C (Colin); CCP4BB@JISCMAIL.AC.UK > Cc: Richard Gillilan > Subject: RE: [ccp4bb] Structural importance of ordered water? > > Surely protein-water > system is energetically happier than protein-vacuum but I don't think > protein-water is as happy as water-water.
Hi, IMHO you can't make such blanket statements without some qualification. The very fact that a protein is soluble in water under given conditions implies that the protein-water interactions created upon dissolution are energetically more favourable (I'm talking about free energy of course) than the protein-protein and water-water interactions that they replace. Similarly, protein-water interactions are no doubt more favourable than a protein-vacuum interface if the protein surface in question contains H-bond donors/acceptors, but this is not true (at least not at normal pressures) if the protein surface is purely non-polar. This was convincingly demonstrated for a T4 lysozyme mutant (http://www.pnas.org/cgi/reprint/102/46/16668.pdf) where water molecules could only be induced (reversibly) to enter a large (160 Ang^3) rigid hydrophobic void in the protein's interior created by the L99A mutation by application of extreme external pressure (200 Mpascals, or 2000 x atmospheric pressure). Cheers -- Ian 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. Astex Therapeutics Ltd., Registered in England at 436 Cambridge Science Park, Cambridge CB4 0QA under number 3751674
