Cell-Permeable and Plasma-Stable Peptidomimetic Inhibitors of the Postsynaptic Density-95/N-Methyl-d-Aspartate Receptor Interaction
摘要:
The protein protein interaction between the NMDA receptor and its intracellular scaffolding protein, PSD-95, is a potential target for treating ischemic brain diseases, neuropathic pain, and Alzheimer's disease. We have previously demonstrated that N-alkylated tetrapeptides are potent inhibitors of this interaction, and here, this template is exploited for the development of blood plasma-stable and cell-permeable inhibitors. Initially, we explored both the amino acid sequence of the tetrapeptide and the nature of the N-alkyl groups, which consolidated N-cyclohexylethyl-ETAV (1) as the most potent and selective compound. Next, the amide moieties of N-methylated ETAV were systematically replaced with thioamides, demonstrating that one of three amide bonds could be :replaced without compromising the affinity. Subsequent optimization of the N-alkyl groups and evaluation of cell permeability led to identification of N-cyclohexylethyl-ETA(s)V (54) as the most potent, plasma-stable and cell-permeable inhibitor, which is a promising tool in unraveling the therapeutic potential of the PSD-95/NMDA receptor interaction.
Efficient N-Terminal Labeling of Proteins by Use of Sortase
作者:Daniel J. Williamson、Martin A. Fascione、Michael E. Webb、W. Bruce Turnbull
DOI:10.1002/anie.201204538
日期:2012.9.10
“Sorting out” N‐terminal labeling: The reversibility of transpeptidase reactions makes protein N‐terminal labeling challenging. Depsipeptide substrates for sortase A release alcohol by‐products, which are poor nucleophiles for the reverse reaction, during ligation. Proteins with an unhindered N‐terminal glycine residue can be labeledefficiently with only a minimal excess of the labeling reagent (see scheme)
“整理” N 端标记:转肽酶反应的可逆性使蛋白质 N 端标记具有挑战性。分选酶 A 的缩肽底物在连接过程中释放醇副产物,这些副产物是逆反应的不良亲核试剂。具有不受阻碍的 N 末端甘氨酸残基的蛋白质只需少量过量的标记试剂即可有效标记(见方案)。