3zrt | pdb_00003zrt
Crystal structure of human PSD-95 PDZ1-2
Structural highlights
Function[DLG4_HUMAN] Interacts with the cytoplasmic tail of NMDA receptor subunits and shaker-type potassium channels. Required for synaptic plasticity associated with NMDA receptor signaling. Overexpression or depletion of DLG4 changes the ratio of excitatory to inhibitory synapses in hippocampal neurons. May reduce the amplitude of ASIC3 acid-evoked currents by retaining the channel intracellularly. May regulate the intracellular trafficking of ADR1B (By similarity). Publication Abstract from PubMedInhibition 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. A high-affinity, dimeric inhibitor of PSD-95 bivalently interacts with PDZ1-2 and protects against ischemic brain damage.,Bach A, Clausen BH, Moller M, Vestergaard B, Chi CN, Round A, Sorensen PL, Nissen KB, Kastrup JS, Gajhede M, Jemth P, Kristensen AS, Lundstrom P, Lambertsen KL, Stromgaard K Proc Natl Acad Sci U S A. 2012 Feb 28;109(9):3317-22. Epub 2012 Feb 17. PMID:22343531[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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