In theory, what you say is quite sensible. But there is one interesting counter example I am aware of. The fragment tool compound that eventually gave rise to the clinical compound indeglitazar ( http://www.pnas.org/content/106/1/262.full.pdf) gives a negative shift by DSF (in our hands): [image: Inline image 1]
Therefore, this experience taught us to bin compounds that are negative and positive and follow up on both, prioritizing depending on this and any other data we might have. In the end, we don't overthink it and just put them in other assays and crystallography if appropriate. Waving my hands around, you might imagine a scenario where the dye itself binds and stabilizes a folded form of the protein. If the fragment also binds AND displaces the dye AND the fragment stabilizes the protein LESS effectively than the dye, THEN I believe you could have a true binder that gives a negative shift. Nick On Sat, Jul 8, 2017 at 8:30 PM, megha abbey <abbey...@gmail.com> wrote: > Hello, > > I am working on DSF to verify if some compounds bind to my protein. I see > a negative shift of about 3-4 degrees upon ligand addition (dose-response) > in comparison to the protein alone. I assume that this might be due to the > binding of compound to the unfolded stated rather than folded protein. > > In such a situation where compounds are to be screened with the aim of > drug discovery, are these negative thermal shift compounds relevant and how > can they be followed upon, or they should simply be discarded? > > Thank you. > -- [This e-mail message may contain privileged, confidential and/or proprietary information of H3 Biomedicine. If you believe that it has been sent to you in error, please contact the sender immediately and delete the message including any attachments, without copying, using, or distributing any of the information contained therein. This e-mail message should not be interpreted to include a digital or electronic signature that can be used to authenticate an agreement, contract or other legal document, nor to reflect an intention to be bound to any legally-binding agreement or contract.]
