What are you using to dissolve the compounds? If DMSO or other organics, you maybe witnessing unfolding due to the organics. Have you done a control of just the solution with the protein.
Some compounds may drastically change the pH of the buffer your protein is in. You maybe observing a change in the stability of your protein due to pH change. You could also try the same compounds against BSA, lysozyme and other control proteins to see if you observe a similar effect. Dan Get Outlook for Android<https://aka.ms/ghei36> From: megha abbey Sent: Saturday, 8 July, 20:30 Subject: [ccp4bb] off-topic: negative thermal shift upon ligand binding To: ccp4bb@jiscmail.ac.uk 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.
