I believe medicinal chemists do indeed talk about "enthalpic
interactions". Frank
On 19/09/2018 10:40, Stefano Trapani wrote:
Le 2018-09-18 19:31, Daniel M. Himmel, Ph. D. a écrit :
(where hydrophobic interactions result from van der Waals forces in
an aqueous environment).
Hi
I am not sure that, if one is to give a concise definition of
hydrophobic "interactions", this would be a convenient one, because it
may lead someone to identify vdW forces as the main factor that
maintains apolar aggregated molecules together in aqueous environment.
I have seen many students (and PhD's) believing to the equality:
hydrophobic 'forces'=vdW forces (and not understanding, for example,
that the side chains of a Ser and an Ile can also establish vdW
interactions).
It is true that apolar groups that aggregate establish van der Waals
interactions (like any molecule in contact with another one) but these
microscopic (real) forces are not (as far as I know) the main reason
of aggregation in aqueous environment.
The hydrophobic effect seem to be of a mainly entropic nature (and it
has much more to do with hydrogen bonds than van der Waals forces):
https://en.wikipedia.org/wiki/Hydrophobic_effect#Cause
https://en.wikipedia.org/wiki/Entropic_force#Hydrophobic_force
Being mainly of an entropic nature, hydrophobic "contacts" are not the
direct result of real microscopic "forces" that act between apolar
groups. The terms "forces" and "interactions" in widely used
expressions like "hydrophobic forces" and "hydrophobic interactions"
are somehow misleading.
Best
---
Stefano Trapani
Maître de Conférences
http://www.cbs.cnrs.fr/index.php/fr/personnel?PERS=Stefano%20Trapani
-------------------------------------
Centre de Biochimie Structurale (CBS)
29 rue de Navacelles
34090 MONTPELLIER Cedex, France
Tel : +33 (0)4 67 41 77 29
Fax : +33 (0)4 67 41 79 13
-------------------------------------
Université de Montpellier
CNRS UMR 5048
INSERM UMR 1054
-------------------------------------
--
This message has been scanned for viruses and
dangerous content by *MailScanner* <http://www.mailscanner.info/>, and is
believed to be clean.
------------------------------------------------------------------------
To unsubscribe from the CCP4BB list, click the following link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
########################################################################
To unsubscribe from the CCP4BB list, click the following link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
