Dear colleagues,

as a part of our study on cyclophilins (Cyps), I wanted to test the well-known and strong interaction of CypA to cyclosporin A (CsA) on isothermal titration calorimetry (using Malvern PAEQ-ITC). According to literature, I opted for the reverse ITC setup with protein in the syringe. I performed a dialysis to get glycerol out of the protein stock and to match the cell and syringe buffer composition.

Still, I observed baseline shifts and also extreme noise increases during the ITC experiments (pictures). I suspect partial denaturation during the dialysis and the protein becoming “sticky”, but I am no expert in the area. Any ideas of what could be happening? Any tips on how to prevent it?

Thank you very much in advance.