Hi Amit, They are related but different. van der Waals (dispersion-attraction/repulsion, London) forces are real forces arising from instantaneous-induced dipoles. Whereas in most quantitative treatments in biophysics they have an arbitrary component (e.g., the exact way to represent the repulsive term in a classic function is open to debate), they do represent real forces and interactions, as classically understood.
Hydrophobic "interactions" are not formally interactions at all, they are preferential associations reflecting a less favorable energy in the solvated state. Thus there is no hydrophobic interaction between groups and atoms, there is rather the higher free energy of the solvated state that drives them together, reducing the free energy of the system. Hydrophobicity is one step more complicated still, in that it reflects changes in the heat capacity of the system (moving from a solvated --> buried hydrophobic interface reduces the heat capacity at room temperature, in an aqueous environment). Indeed, the formal way to measure a hydrophobic effect is to show that there is a substantial DCp in the process. This, and the behavior of water, makes the hydrophobic effect highly temperature dependent. A hydrophobic "driving force" at one temperature can disappear at another temperature. The reason hydrophobic effects and van der Waals interactions are often conflated is that the same sort of non-polar atoms lead to both. But of course polar atoms also interact through van der Waals interactions. Hope this helps. brian On Fri, Jul 2, 2021 at 10:50 AM amit gaur <[email protected]> wrote: > Hi everyone, > I hope everything is going well with all of you. I want to > know that, Are hydrophobic and vander waal forces are similar? and what is > criteria for formation of these and interatomic distances needed to form > these interactions between amino acids? What kinds of atoms have propensity > to form these interactions? > > Thank you, > -- > *Dr. Amit Gaur* > > *Research AssociateThomas Jefferson University* > *Department of Translational medicine* > *1020, Locust Street, Jefferson Alumni Hall* > *Philadelphia, PA 19107* > > > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > -- Brian Shoichet, Professor, UCSF latest science from the lab: *http://www.bkslab.org/ <http://www.bkslab.org/contact.php>* ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
