A high-affinity, dimeric inhibitor of PSD-95 bivalently interacts with PDZ1-2 and protects against ischemic brain damage

Research output: Contribution to journalJournal articleResearchpeer-review

Anders* Bach, Bettina H Clausen, Magda Møller, Bente Vestergaard, Celestine N Chi, Adam Round, Pernille Louise Sørensen, Klaus Bertram Nissen, Jette Sandholm Kastrup, Michael Gajhede, Per Jemth, Anders Skov Kristensen, Patrik Lundström, Kate Lykke Lambertsen, Kristian* (*Corresponding) Strømgaard

Inhibition of the ternary protein complex of the synaptic scaffolding protein postsynaptic density protein-95 (PSD-95), neuronal nitric oxide synthase (nNOS), and the N-methyl-d-aspartate (NMDA) receptor is a potential strategy for treating ischemic brain damage, but high-affinity inhibitors are lacking. Here we report the design and synthesis of a novel dimeric inhibitor, Tat-NPEG4(IETDV)(2) (Tat-N-dimer), which binds the tandem PDZ1-2 domain of PSD-95 with an unprecedented high affinity of 4.6 nM, and displays extensive protease-resistance as evaluated in vitro by stability-measurements in human blood plasma. X-ray crystallography, NMR, and small-angle X-ray scattering (SAXS) deduced a true bivalent interaction between dimeric inhibitor and PDZ1-2, and also provided a dynamic model of the conformational changes of PDZ1-2 induced by the dimeric inhibitor. A single intravenous injection of Tat-N-dimer (3 nmol/g) to mice subjected to focal cerebral ischemia reduces infarct volume with 40% and restores motor functions. Thus, Tat-N-dimer is a highly efficacious neuroprotective agent with therapeutic potential in stroke.
Original languageEnglish
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue number9
Pages (from-to)3317-3322
ISSN0027-8424
DOIs
Publication statusPublished - 28 Feb 2012

Bibliographical note

Keywords: drug discovery; ischemic stroke; protein-protein interactions

ID: 37796948