Abstract:

The seminar presents the most significant results of investigations aimed at characterizing the interaction of hydrophobic and hydrophilic porphyrins with globular proteins. We have used optical spectroscopy to characterize the binding parameters such as dissociation constant, number of binding sites and number of porphyrin molecules bound to each protein. One of the model proteins, b-lactoglobulin, undergoes a pH dependent conformational change that modulates the binding to the interior pocket of the protein. The effect of irradiation of the porprhyrins on the conformation of the proteins have also been investigated with spectroscopic techniques. Recent results of interaction with tubulin will also be presented. This is particularly interesting because of the similarity with the interaction of the protein with paclitaxel.  Porphyrin-mediated damage of proteins could represent a breakthrough in cancer phototherapy but it also opens possibilities for application in biotechnology, biosensors and proteomics.