Phospholipids are important membrane components involved in diverse biological activities ranging from cell signaling to infection by viral particles. A thorough understanding of protein-phospholipid interaction dynamics is thus crucial for deciphering basic cellular processes as well as for targeted drug discovery. For any specific phospholipid-protein binding experiment, various groups have reported different binding constants, which are strongly dependent on applied conditions of interactions. Here, we report a method for accurate determination of the binding affinity and specificity between proteins and phospholipids using a model interaction between PLC-d1/PH and phosphoinositide phospholipid PtdIns(4,5)P2. We developed an accurate Force Distance Spectroscopy (FDS)-based assay and have attempted to resolve the problem of variation in the observed binding constant by directly measuring the bond force. We confirm the FDS findings of a high bond strength of ~0.19 ± 0.04 nN by Surface Plasmon Resonance (SPR) data analysis, segregating non-specific interactions, which show a significantly lower K(D) suggesting tight binding.
View details for DOI 10.1039/c5an00498e
View details for Web of Science ID 000356171400028
View details for PubMedID 26040325