Analysis Of The Interaction Between Ligands And PICK1

PICK1 (protein interacting with Ca kinasel) was found in yeast two hybrid and distributes in tissues. PICK1 participates in many physiological functions such as learning, nerve transmission and regulation, cell growth and adhesion, membrane pinocytosis and phagocytosis. And it plays important role in cancer, schizophrenia, pain, Parkinson’s disease, depression and so on. It is suggest that PICK1 PDZ domain is regarded as a potential drug target protein.PICK1 is 416 residues in length containing a single N-terminal PDZ domain and acidic amino region as well as C-terminal Bar domain and acidic amino region. PICK1 PDZ domain is consist of six β strands (βA-βF) and two a helix (αA-αB). An elongated groove between the βB strand and the aB helix of the PDZ domain recognize and bind 3-4 amino acid sequence of C terminal in its interacting partner. It has been found that PICK1 can interact with over 60 proteins, and the interaction between them is achieved by PDZ domain. PDZ domain plays key role in protein-protein interaction and protein complex formation.Firstly, we obtained PICK1-PDZ domain soluble protein by gene cloning and recombination, protein expression and purification. Secondly, we compared the binding ability of PDZ domain with three compounds (chlorogenic acid, caffeic acid, hyperin) using fluorescence spectroscopy. Thirdly, we verified the interaction between PDZ domain and chlorogenic acid by CD and NMR. Finally, we find that chlorogenic acid can compete against GluR2C for binding PICK1-PDZ domain by fluorescence polarization and bimolecular fluorescence complementation.In addition, we analyzed the interaction of between PICK1 and a-SNAP. Serine racemase was also expressed and purified here.