Establishment of a screening model for compounds uncoupling the interaction of nNOS with PSD-95 / 药学学报

In ischemic stroke, increased level of neuronal complex of nitric oxide synthase (nNOS)-postsynaptic density protein-95 (PSD-95) plays an important role in neuronal damage. We aimed to establish a screening model to identify compounds capable of uncoupling nNOS interaction with PSD-95. In this model, human embryonic kidney-293T (HEK-293T) cells were transfected with either pCDH-Flag-nNOS or pcDNA3.1-PSD-95 plasmid to obtain the protein of Flag-nNOS or PSD-95. Incubating Flag-nNOS with PSD-95 causes formation of the nNOS-PSD-95 complex. ZL006, a known uncoupler of nNOS-PSD-95 interaction, can disturb the interaction between Flag-nNOS and PSD-95, serving as a positive control. The method coupling antibodies to magnetic beads with glutaraldehyde was used to decrease the cost and increase the efficiency. To establish that our model is suitable for selecting nNOS-PSD-95 uncouplers, we evaluated the ability of IC87201, another reported uncoupler of nNOS-PSD-95 interaction, and structural analogs of ZL006. IC87201 and one structure analog of ZL006 showed uncoupling effect, supporting that our model can be used to select different types uncoupler blocking nNOS-PSD-95 interaction.

Efficient discovery and capturing of nNOS-PSD-95 uncouplers from Trifolium pratense / 中国中药杂志

Magnetic molecularly imprinted polymers(MMIPs) were prepared with ZL006 as template, acrylamide(AA) as the functional monomer, and acetonitrile as pore-forming agent; then Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscopy(SEM) were used to characterize their forms and structures. Simultaneously, the MMIPs prepared previously were used as sorbents for dispersive magnetic solid phase extraction(DSPE) to capture and identify potential nNOS-PSD-95 uncouplers from extracts of Trifolium pratense and the the activities of the screened compounds were evaluated by the neuroprotective effect and co-immunoprecipitation test. The experiment revealed that the successfully synthesized MMIPs showed good dispersiveness, suitable particle size and good adsorption properties. Formononetin, prunetin and biochanin A were separated and enriched from Trifolium pratense by using the MMIPs as artificial antibodies and finally biochanin A was found to have higher cytoprotective action and uncoupling action according to the neuroprotective effect and co-immunoprecipitation test.